Application Notes 2014
Terminology - Protection - Application Examples - Tips and Tricks
SMD Reflow Soldering - Internal Block - Diagrams - Packaging
Filtering - Isolation - EMC

Application Notes
SPECIFICATION CHECKLISTUse this checklist to help you define your specification. If you can’t find a converter that fulfils yourneeds then call us, fax us, e-mail us or use our Web Sample Enquiry link and we will find the best
match for you.
1.

c Non-Isolatedc Isolation Required _____kVDC or ____kVAC

2.

c Single Output

c Dual Bipolar Output

c Other:

Output Voltages (V) _____ /______/______
Output Currents (A) _____/______/______
3.

Total Output Power (V x A) _________________

4.

c Regulated

5.

Short Circuit Protection: c No c Yes

6.

Remote Control Pin: c No c Yes

7.

Output Voltage Trim: c No c Yes

8.

Input Voltage: minimum ______ maximum ______

9.

Mounting Style: c Through Holec Unregulatedc SMD

Single-In-Line Pins c SIP4 c SIP6 c SIP7
c SIP8c SIP12Dual-In-Line Pins c DIP8 c DIP14 c DIP16 c DIP24 - Pinout? A_B_C_
Standard Brickc 1” x 1” c 1” x 2” c 1.6” x 2” c 2” x 2”
Case Style: c Metal Casec Plastic Casec Open Frame

10.

Certifications Required: c None c EN 60950-1 c EN 60601-1 c UL 60950-1

11.

Operating Temperature Range: minimum ______ maximum ______

12.

Heatsink required : c No c Yes

13.

Other Requirements:________________________________________REMEMBER: THERE IS AN INTERACTIVE SELECTION GUIDE ON OUR WEBSITESRECOM makes every effort to ensure that the
specifications in this catalogue are complete
and accurate. RECOM reserves the right toalter or improve the specification, internal design or manufacturing process at any time,

APP NOTES

without notice. Please check with yoursupplier that you have the most current andcomplete specification for your productbefore use. Customers may check that they
have the most up to date datasheets by

2014

visiting the RECOM website at:www.recom-international.com
www.recom-power.com,
www.recom-asia.com or by calling or sending an e-mail to RECOM Technical Support.

www.recom-international.com

Application Notes
CHOOSING THE RIGHT CONVERTER: A GUIDE for DC/DC Converters
Step 1:

Do you need Isolation? (An isolated converter has outputs that are floating and notconnected to the inputs i.e. they are galvanically isolated)
No isolation needed: Check our Innoline parts first (R-78 series, R-5xxx, R-6xxx and
R-7xxx series)
Isolation needed: decide whether you need 1kVDC/1 sec (standard) or 1.6VDC/
1 sec, 2kVDC/1 sec, 3kVDC/1 sec, 4kVDC/1 sec, 5.2kVDC/1 sec or 6kVDC/1 sec.

Step 2:

Decide on the output voltage and number of outputs: single, dual bipolar (+/-), dual
isolated or triple.
It is also important to decide whether the output voltage needs to be regulated or
unregulated.
Unregulated converters are offered standard without short circuit protection or
optionally with short circuit protection (option /P)
All Series are available with single outputs.
Please note that a dual output converter can be used as a single output by leaving
the common pin unconnected i.e. +/-5V = 10V, +/-12V = 24V, +/-15V = 30V, etc.

Step 3:

Decide on the output current. The output voltage times the output current gives theoutput power of the converter in Watts.
DC/DC converters are designed to run at full load, so only round up the power if asuitable converter is not available.
e.g. 5V @ 150mA = 0.75W = 1W converter.
e.g. +/-15V @ +/-1A = 30W = 30W converter.

Step 4:

Decide on the input voltage. Standard input voltage ranges are:3.3, 5, 9, 12, 15, and 24VDC with +/-10% tolerance
4.5 ~ 9V, 9 ~ 18V, 18 ~ 36V and 36 ~ 72VDC with 2:1 input voltage range
9 ~ 36V and 18 ~ 72VDC with 4:1 input voltage range.

Step 5:

Decide on the case style and pin-out. Many Recom series are available in either
through hole or surface mount styles and with several pin-out options, including
Remote On/Off Control.

Step 6:Use either the Selection guide or Contents guide at the start of each section tofind the most appropriate converter.

REMEMBER: THERE IS AN INTERACTIVE SELECTION GUIDE ON OUR WEBSITESRECOM makes every effort to ensure that the
specifications in this catalogue are complete
and accurate. RECOM reserves the right toalter or improve the specification, internal design or manufacturing process at any time,www.recom-international.com

without notice. Please check with yoursupplier that you have the most current andcomplete specification for your productbefore use. Customers may check that they
have the most up to date datasheets by

2014

visiting the RECOM website at:www.recom-international.com
www.recom-power.com,
www.recom-asia.com or by calling or sending an e-mail to RECOM Technical Support.

APP NOTESApplication Notes
Contents
ECONOLINE (General Apps.)●

Pre- and Post Regulation●

Output Voltage Accuracy

Terminology

EIA-232 Interface●

Voltage Balance

Input Range

3V/5V Logic Mixed Supply Rails●

Line Regulations

Load Regulation

Isolated Data Acquisition System●

Load Regulation

EMC Considerations●

Efficiency

Output Voltage Accuracy

Power Supply Considerations●

Switching Frequency

Input and Output Ripple and NoiseInterpretation of DC-DC Converter EMC Data●

Output Ripple and Noise

Input to Output Isolation

Conducted and Radiated Emissions●

Output Ripple and Noise (continued)

Insulation ResistanceLine Impedance Stabilisation Network (LISN)●

Transient Recovery Time

Efficiency at FulI Load

Shielding●Current Limiting

Temperature Drift

Line Spectra of DC-DC Converters●

Fold Back Current LimitingLine Voltage Regulation●

Switching Frequency●

Temperature Performance of DC-DC Converters●

Isolation

No Load Power Consumption●

Transfer Moulded (SMD) DC-DC Converters●

Break-Down Voltage

Isolation Capacitance

Production Guideline Application Note●

Temperature Coefficient

Mean Time Between Failure (MTBF)

Component Materials●

Ambient Temperature

Noise

Component Placement●

Operating Temperature Range

Operating Temperature Range

Component Alignment●

Storage Temperature Range

Calculation of Heatsinks

Solder Pad Design●

Output Voltage Trimming

Isolation

Solder Reflow Profile●

Heat Sinks

Isolation Voltage vs. Rated Working Voltage

Recommended Solder Reflow Profile

POWERLINE AC/DC●

Isolation mode in IGBT Driver Circuits

Adhesive Requirements●

Connecting DC-DC Converters in Series

Adhesive Placement●

Connecting DC-DC Converters in Parallel

Cleaning●

Chaining DC-DC Converters

Vapour Phase Reflow Soldering●

Filtering●●

Tin Whisker Mitigation●

Input Fuse●

Earthing●

External Filter●

Paralleling AC/DC Converters●

Chaining Converters●

DC Inputs

Output Filtering Calculation●

Limiting Inrush Current●

Maximum Output Capacitance●

Settling Time●

Isolation Capacitance and Leakage Current●

Application Examples
Overload Protection
Input Voltage Drop-Out (brown-outs)

INNOLINE●

EMC Filter Suggestion●

Soft Start Circuit●

Positve - to - Negative Converters

POWERLINE DC-DC●

EMC Filter Suggestion●

General Test Set-Up●

Input Voltage Range●

PI Filter

No Load Over Voltage Lock-Out

POWERLINE PLUS●

IEC Technology●

Trim Tables●

Block Diagrams

BLOCK DIAGRAMSLong Distance Supply Lines
LCD Display Bias

A-0

2014

Transport Tubes & Reels

www.recom-international.com

DC-DC Converter Applications
Terminology
The data sheet specification for DC-DC converters contains a large quantity of information.
This terminology is aimed at ensuring that theuser can interpret the data provided correctly
and obtain the necessary information for theircircuit application.
Input Range
The range of input voltage that the device cantolerate and maintain functional performanceover the Operating Temperature Range at fullload.
Load Regulation
The change in output voltage over the specified
change in output load. Usually specified as apercentage of the nominal output voltage, forexample, if a 1V change in output voltage ismeasured on a 12V output device, load voltage
regulation is 8.3%. For unregulated devices
the load voltage regulation is specified overthe load range from 10% to 100% of full
load.
Line Voltage Regulation
The change in output voltage for a givenchange in input voltage, expressed as percentages. For example, assume a 12V in-put, 5V
output device exhibited a 0.5V change at theoutput for a 1.2V change at the input, line
regulation would be 10%/10%.
Output Voltage Accuracy
The proximity of the output voltage to thespecified nominal value. This is given as atolerance envelope for unregulated devices
with the nominal input voltage applied. For example, a 5V specified output device at 100%load may exhibit a measured output voltage of
4.75V, i.e. a voltage accuracy of –5%).
Input and Output Ripple and NoiseThe amount of voltage drop at the input, or
output between switching cycles. The value ofvoltage ripple is a measure of the storage
ability of the filter capacitors. The values givenin the datasheets include the higher frequency
Noise interference superimposed on the ripple
due to switching spikes.The measurement islimited to 20MHz Bandwidth.
Input to Output Isolation
The dielectric breakdown strength test between
input and output circuits. This is the isolation
voltage the device is capable of withstanding
for a specified time, usually 1 second (for moredetails see chapter “Isolation Voltage vs. Rated
Working Voltage”).
www.recom-international.com

Insulation Resistance
The resistance between input and output
circuits. This is usually measured at 500V DC
isolation voltage.
Efficiency at FulI Load
The ratio of power delivered from the device topower supplied to the device when the part isoperating under 100% load conditions at 25°C.
Temperature Drift
The change in voltage, expressed as apercentage of the nominal, per degree change
in ambient temperature. This parameter isrelated to several other temperature dependent
parameters, mainly internal component drift.
Switching Frequency
The nominal frequency of operation of theswitching circuit inside the DC-DC converter.
The ripple observed on the input and output
pins is usually twice the switching frequency,
due to full wave rectification and the push-pull
configuration of the driver circuit.
No Load Power Consumption
This is a measure of the switching circuits
power cunsumption; it is determined with zero
output load and is a limiting factor for the total
efficiency of the device.
Isolation Capacitance
The input to output coupling capacitance. This
is not actually a capacitor, but the parasitic
capacitive coupling between the transformer
primary and secondary windings. Isolation
capacitance is typically measured at 1 MHz toreduce the possibility of the on-board filter
capacitors affecting the results.
Mean Time Between Failure (MTBF)
RECOM uses MIL-HDBK-217F standard for
calculation of MTBF values for +25°C as well as
for max. operating temperature and 100% load.
When comparing MTBF values with othervendor's products, please take into account thedifferent conditions and standards i.e. MILHDBK-217E is not as severe and therefore values
shown will be higher than those shown by RECOM.
(1000 x 10³ hours =1000000 hours = 114 years!)
These figures are calculated expected device
lifetime figures using the hybrid circuit model of
MIL-HDBK-217F. POWERLINE converters also
can use BELLCORE TR-NWT-000332 for
calculation of MTBF. The hybrid model has
various accelerating factors for operating
environment (πE), maturity (πL), screening (πQ),
hybrid function (πF) and a summation of eachindividual component characteristic (λC).
2014

The equation for the hybrid model is then givenby:λ = Σ (NC λC) (1 + 0.2πE) πL πF πQ(failures in 106 hours)
The MTBF figure is the reciprocal of this value.
In the data sheets, all figures for MTBF aregiven for the ground benign (GB) environment(πE = 0.5); this is considered the mostappropriate for the majority of applications inwhich these devices are likely to be used.
However, this is not the only operating
environment possible, hence those users
wishing to incorporate these devices into a
more severe environment can calculate thepredicted MTBF from the following data.
The MIL-HDBK-217F has military environments specified, hence some interpretation ofthese is required to apply them to standard
commercial environments. Table 1 gives
approximate cross references from MIL-HDBK217F descriptions to close commercial equivalents. Please note that these are not implied
by MIL-HDBK-217F, but are our interpretation.
Also we have reduced the number of environments from 14 to 6, which are most appropriate to commercial applications. For a moredetailed understanding of the environments
quoted and the hybrid model, it isrecommended that a full copy of MIL-HDBK217F is obtained.
It is interesting to note that space flight andground benign have the same environment
factors. It could be suggested that the actof achieving space flight should be thedetermining environmental factor (i.e. missile
launch).
The hybrid model equation can therefore be
rewritten for any given hybrid, at a fixed
temperature, so that the environmental factor
is the only variable:
λ = k (1 + 0.2 πE)
The MTBF values for other environment factors
can therefore be calculated from the groundbenign figure quoted at each temperature pointin the data book. Hence predicted MTBF
figures for other environments can be calculated very quickly. All the values will in general
be lower and, since the majority of the mobile
environments have the same factor, a quick
divisor can be calculated for each condition.
Therefore the only calculation necessary is todevide the quoted MTBF fig. by the divisor
given in table 2.

A-1

DC-DC Converter Applications
Environment
GroundBenignπESymbolGB

GroundMobileGM

Naval
ShelteredNS

Aircraft
Inhabited
Cargo

AIC

Space
FlightSF

MissileLaunchML

MIL-HDBK-271F
Description
Non-mobile, temperature andhumidity controlled environments
readily accessible to maintenance
Equipment installed in wheeled or
tracked vehicles and equipment
manually transported
Sheltered or below deckequipment on surface ships or
submarines
Typical conditions in cargocompartments which can beoccupied by aircrew
Earth orbital. Vehicle in neither
powered flight nor in atmospheric
re-entry
Severe conditions relating
to missile launchCommercial Interpretation
or Examples
Laboratory equipment, test
instruments, desktop PC's,
static telecomms
In-vehicle instrumentation,
mobile radio and telecomms,
portable PC's
Navigation, radio equipment
and instrumentation below
deck
Pressurised cabin compartments and cock-pits, in flightentertainment and non-safety
critical applications
Orbital communications satellite, equipment only operated
once in-situ
Severe vibrational shock andvery high accelerating forces,
satellite launch conditions

VO

DC

VIN

DC

GND

0V

a) Single Output

DC

VIN

+VO
0V
-VO

DC

GND

b) Dual Output

VIN
GND

VO1
0V1
VO 2
0V2

DC
DC

c) Twin Isolated Outputs

Table 1: Interpretation of Environmental Factors
Figure 1: Standard Isolated Configurations

Environment
Ground Benign
Ground Mobile
Naval Sheltered
Aircraft
Inhabited
Cargo
Space Flight
Missile Launch

πE
SymbolGB
GM
GNS

πE Divisor
Value
0.5
1.00
4.0
1.64
4.0
1.64

AIC

4.0

1.64

SF
ML

0.5
12.0

1.00
3.09

Table 2: Environmental Factors

Noise
Input conducted noise is given in the line
conducted spectra for each DC-DC converter(see EMC issues for further details). Noise isaffected significantly by PCB layout, measurement system configuration, terminating
impedance etc., and is difficult to quotereliably and with any accuracy other than via aspectrum analysis type plot. There will be some
switching noise present on top of the ripple,
however, most of this is easily reduced by useof small capacitors or filter inductors, as shownin the application notes.

Operating temperature range:
Operating temperature range of the converter
is limited due to specifications of thecomponents used for the internal circuit of theconverter.
The diagram for temperature derating shows
the safe operating area (SOA) within which thedevice is allowed to operate. At very low
temperatures, the specifications are only
guaranteed for full load.
Up to a certain temperature 100% power canbe drawn from the device, above this temperature the output power has to be less toensure function and guarantee specifications
over the whole lifetime of the converter.
These temperature values are valid for naturalconvection only. If the converter is used in aclosed case or in a potted PCB board, higher
temperatures will be present in the area aroundthermal converter because the convection may
be blocked.
If the same power is also needed at higher
temperatures either the next higher wattage
series should be chosen or if the converter hasa metal case, a heatsink may be considererd.
Please refer to the Powerline Application Notes
Section for more information on thermal
impedance and heatsinking.

A-2

2014

VCC
+VO

DC
DC

-VO

0V

GND

a) Non-lsolated Dual Rails
VCC

DC
DC

+VO
0V
-VO

GND

b) Non-lsolated Negative Rail
VCC

DC
DC

+VO
(VO+VIN)
0V

GNDc) Non Isolated Voltage Booster
Figure 2: Alternative Supply Configurations

www.recom-international.com

DC-DC Converter Applications
Isolation
One of the main features of the majority of
Recom DC-DC converters is their high galvanic
isolation capability. This allows several variations
on circuit topography by using a single DC-DC
converter.

bias, resistor feed). Having an alternative return
path can upset the regulation and theperformance of the system may not equal thatof the converter.

The basic input to output isolation can be used
to provide either a simple isolated output powersource, or to generate different voltage rails,
and/or dual polarity rails (see figure 1).
These configurations are most often found in
instrumentation, data processing and othernoise sensitive circuits, where it is necessary
to isolate the load and noise presented to the
local power supply rails from that of the entire
system. Usually local supply noise appears ascommon mode noise at the converter and does
not pollute the main system power supply rails.
The isolated positive output can be connectedto the input ground rail to generate a negative
supply rail if required. Since the output isisolated from the input, the choice of reference
voltage for the output side can be arbitrary, forexample an additional single rail can begenerated above the main supply rail, or offset
by some other DC value (see figure 2).
Regulated converters need more consideration
than the unregulated types for mixing thereference level. Essentially the single supply rail
has a regulator in its +Vout rail only, hencereferencing the isolated ground will only work if
all the current return is through the DC-DC andnot via other external components (e.g. diode

Isolation Voltage vs. Rated Working Voltage
The isolation voltage given in the datasheet isvalid for 1 second flash tested only.
If a isolation barrier is required for longer orinfinite time the Rated Working Voltage has tobe used.
Conversion of Isolation Voltage to Rated
Working Voltage can be done by using thistable or graph.

IEC950 Test Voltage for Electrical Strength Tests

Isolation Test Voltage (V)Rated Working Voltage (V)

1000

130

1500

230

3000

1100

6000

3050

Table 2: Typical Breakdown Voltage Ratings According to IEC950

The graph and table above show the requirements from IEC950. According to our experience and in-house tests, we can offer the following conversion
tables. Please note that these equivalence tables are for information only and that RECOM assumes no resposibility for their use:

DC
1 Sec

1 Min

500VDC

400VDC

1000VDC

800VDC

1500VDC

AC
1 Sec

1 Min

350VAC

250VAC

130VDC

700VAC

500VAC130VAC

1200VDC

230VDC

1080VAC

750VAC230VAC

2kVDC

1.6kVDC

550VDC

1.4kVAC

1kVAC

550VAC

3kVDC

2.4kVDC

1.1kVDC

2.1kVAC

1.5kVAC

1.1kVAC

4kVDC

3.2kVDC

1.8kVDC

2.8kVAC

2kVAC

1.8kVAC

6kVDC

4.8kVDC

3kVDC

4.2kVAC

3kVAC

3kVAC

8kVDC

6.4kVDC

4kVDC

5.6kVAC

4kVAC

4kVAC

10kVDC

8kVDC

5kVDC

7kVAC

5kVAC

5kVAC

www.recom-international.com

Cont.

2014

Cont.

A-3

DC-DC Converter Applications
Isolation mode in IGBT driver circuits
An application for DC/DC converters is to isolate driver circuits for IGBT stacks. In these applications, the maximum DC voltage applied across theisolation gap is not the only factor to be considered because the highly dynamic switching waveforms are an additional stressing factor (typicalswitching transients can exceed 20kV/µs.) Taking into account that both factors mean a permanent stress on the converter, it is recommended toover specify the converter in terms of isolation voltage and coupling capacitance.
Even if a 3kVDC product seems to be appropriate if you just look at the rated working voltage that is required, it is still recommended to choose aproduct which is specified to 5.2kVDC or 6kVDC to also cover the high dv/dt rates. The higher the isolation voltage rating for a DC/DC converter is,
the lower the coupling (isolation) capacitance and a low coupling capacitance is essential in AC or highly dynamic switched DC usage. This will
ensure a safe usage and avoid a shortened lifetime in such a highly demanding situation.
In the example below, A RP-0524S is used to provide a 5200V isolated supply for the high side drivers and a second, non-isolated converter isused to boost the 5V supply voltage up to 15V for the low side drivers.

Connecting
DC-DC Converters in Series
Galvanic isolation of the output allows multiple
converters to be connected in series, simply byconnecting the positive output of one converterto the negative of another (see figure 3). In thisway non-standard voltage rails can begenerated, however, the current output of thehighest output voltage converter should not be
exceeded.

When converters are connected in series,
additional filtering is strongly recommended, as
the converters switching circuits are notsynchronised. As well as a summation of theripple voltages, the output could also produce
relatively large beat frequencies. A capacitor
across the output will help, as will a series
inductor (see filtering).

Vcc

DC
DC
DC
DC

+Vo
0V
+Vo

2Vo

0V

GND
Figure 3: Connecting DC-DC Converters in Series

A-4

2014

www.recom-international.com

DC-DC Converter Applications
Connecting
DC-DC Converters in Parallel

Example 1:100W DC/DC Power Supply

Connecting the outputs of DC/DC converters inparallel is possible but not recommended.
Usually DC/DC converters have no possibility
to balance out the output currents.

DC/DC
Converter 1
RPP50-2405S

Si7495DP

+Vout

-Vout
E1

So there is potential danger that if the loading
is asymmetrical, that one of the converters
starts to be overloaded while the others have todeliver less current. The
over-loaded
converter may then drop out of circuit leading
to power supply oscillation.

V1

GND Load Share
E2

Controller
LTC4416
V2

5V @ 20A

G1
Vs
G2

+Vout

DC/DC
Converter 2
RPP50-2405S

The only possibility to balance out theindividual currents is to use a converter with a
special load balance function (like the R-5xxx
series- see Figure 4) or to use the converters
with an external load-share controller.

Si7495DP-Vout

Example 2: 3.3V @8A POL Power Supply

Vcc

DC

+V

+Vin

DC
Balance
Link

+

100µF

GND

E1

+

DC
DC

Si7495DP

+Vout

DC/DC
Converter 1
R-743.3P

V1

GND Load Share

3.3µF

E2

0V

Controller
LTC4416
V2

3.3V @ 8A

G1
Vs
G2

GND
+Vin

Figure 4: Paralleled DC-DC Converters with Balance
Function.

LOAD SHARE CONTROLLER
Refer to figure 5 for some application examples using the LTC4416 Dual PowerPath controller and two external FETs. The load sharecontroller IC can balance out the load currents
as long as the outputs are within 500mV ofeach other.
If two or more converters are operated from acommon supply voltage (inputs in parallel),then input decoupling via LC-filters is
recommended. This helps to avoid hard-tohandle conducted EMI caused by thenon-synchronized oscillators. Also inrush
current peaks are lowered. Having several
smaller filters, one for each converter, is recommended instead of using one common filter for all converters, as this helps to reduce
the possibility of the converters beating against
each other.

Chaining
DC-DC Converters
Connecting the output of one DC/DC converterto the input of a second converter is sometimes a very useful technique. For example, thebenefits of the very wide input voltage rangeof the innoline series can be combined with thehigh isolation of the econoline series to create
a combination converter which is both isolatedwww.recom-international.com

3.3µF

+

DC/DC
Converter 2
R-743.3P+Vout+

Si7495DP
100µF

GND

Figure 5: Doubling Output Power via Paralleled DC-DC Converters and a Load Share Controller

and with an exceptionally wide 7:1 input
voltage range.

Vcc = 5V

DC

Similarly, an isolated DC/DC converter can beused to power a R-78 switchning regulator toprovide dual positive outputs with nonstandard voltages.
In every case, some care has to be taken
concerning the inrush current of the second
converter in the chain. If the peak inrush
current is too high, then then the first
converter in the chain may not start up.
The solution to this problem is to add some
capacitance to supply the peak inrush current
and/or to delay the start-up of the second
converter in the chain.
Figure 5a shows some typical examples.

2014

+12V

REC5-0512SRW/H6/A

DC

+Vo
-Vo

10µ

R-783.3
-0.5

0V

GND

+15V

Vcc = 9-39V
RP15-2415SAW

DC
DC

GND

+3.3V

RP08-1205DA

+Vo
C1

-Vo

DC
CTRL

DC

+5V

0V

-5V

RP08 starts up after delay
C1 provides inrush start up current

Figure 5a: Chained DC-DC Converter Examples

A-5

DC-DC Converter Applications
Filtering
When reducing the ripple from the converter,
at either the input or the output, there areseveral aspects to be considered. Recom
recommend filtering using simple passive LC
networks at both input and output (see figure6). A passive RC network could be used,however, the power loss through a resistor isoften too high.The self-resonant frequency of
the inductor needs to be significantly higher
than the characteristic frequency of thedevice (typically 1OOkHz for Recom DC-DC
converters). The DC current rating of theinductor also needs consideration, a rating ofapproximately twice the supply current isrecommended.
The DC resistance of the inductor is the final
consideration that will give an indication of
the DC power loss to be expected from theinductor.

Output Filtering calculation:
Calculating of the filtering components can bedone using

This frequency should be significant lower than
the switching frequency of the converter.
Example - RC series:
Operating frequency = 85kHz max.
then, fc =10 % of 85 kHz = 8,5 kHz

LIN

DC

VIN

CIN

DC

GND

When choosing a value for the filtering capacitor
please take care that the maximum capacitive
load is within the specifications of the converter.

A-6

CO
CO
LOUT

+VOUT
0V
-VOUT

Figure 6: Input and Output Filtering

Common Mode Chokes
Better results in filtering can be achieved if
common mode chokes are used instead of asingle choke.
Common mode chokes are multiple chokes
sharing a core material so the common mode
rejection (Electrical noise which comes throughone power line and returns to the noise source
through some type of ground path is common
mode noise.) is higher.
Please refer to our page "Common Mode
Chokes for EMC" also part of these application
notes. These can be used for input filtering aswell as for the output side.

Limiting Inrush Current
Using a series inductor at the input will limit
the current that can be seen at switch on(see figure 7).
If we consider the circuit without the series
inductor, then the input current is given by;

This would imply that for a 5V input, with say
50mOhm track and wire resistance, the inrush
current could be as large as 1OOA. This could
cause a problem for the DC-DC converter.
A series input inductor therefore not only filters
the noise from the internal switching circuit,
but also limits the inrush current at switch on.
A typical value for an input inductor used toreduce the inrush current is 1mH or higher.
A typical value for an inductor used to filter the
input is 50-300µH. So although the circuit
diagram may look similar, the input inductors
have very different functions and different
values.
If a common mode choke is used as an inrush
current limiter, it has the added advantage overa single inductor that the inrush currents flowing
in the two windings cancel out and the ferrite isless likely to go into saturation.

Short Circuit Protection in
0.25W - 2W Econoline converters
In the low wattage, unregulated converter Portfolio we offer continuous short circuit protection (option /P). Especially in applications where
the output of converters is connected via a plugand socket to an external module, the chancesof having a short circuit across the output isquite high. A conventional unregulated converter can withstand a short circuit across the outputs for only a limited time. The same condition
can occur with high capacitive loads if they havea low ESR.

i = V exp – t
R
RCRECOM uses balancing between transformer
core saturation ratings and the maximum electrical ratings of the switching transistors in the
primary side oscillator to create a converter thatcan withstand a continuous short circuit(<1 Ohm) across the outputs without failing.

When the component is initially switched on(i.e. t=O) this simplifies to;
i=VR

However, this is NOT an overload protection.
If the coverters are over-loaded but not shortcircuited, the converters may still overheat and
fail.

Figure 7: Input Current & Voltage at Switch On

However, depending on your application designand loadsituation may interfer with thecalculated filter so testing in the final
application and re-adjustment of thecomponent’s values may be necessary.

LOUT

( )

2014

www.recom-international.com

DC-DC Converter Applications
Maximum Output Capacitance
A simple method of reducing the output ripple
is simply to add a large external capacitor. Thiscan be a low cost alternative to the LC filter
approach, although not as effective. There is,however, also the possibility of causing start
up problems, if the output capacitance is toolarge.
Recom uses the following definition for maximum capacitive load: “the maximum output
capacitance that permits start-up in less than
one second and does not damage the converter”
With a large output capacitance at switch on,
there is no charge on the capacitors and the
DC-DC converter immediately experiences alarge current demand at its output. The inrush
current can be so large as to exceed theability of the DC-DC converter, and the device
can go into current limit.
For converters with a constant power limit,
the effect of a large capacitive load is tomake the output voltage slowly ramp up
over time. However, for converters with ahiccup protected output, the device could
continuously oscillate as it tries to start, goes
into overload shutdown and then retries again.
The DC-DC converter may not survive if thiscondition persists.
For unregulated converters, the overload
condition caused by the capacitor charging

current could damage the converter. If
instead of single capacitors on outputs an
RC-filter or LC-Filter is used, the maximum
capacitive load can be higher because theresistor/choke reduces the capacitor inrush
current peak. However, fairly large resistors or
inductances are required to have a meaningful
effect.

be calculated.

Settling TimeThe general isolation impedance equation for agiven frequency (f) is given by:

The main reason for not fitting a series
inductor internally, apart from size constraints,
is that many applications require a fast switch
on time. When the input voltage is a fast ramp,
then the output can respond within 500µs of
the input reaching its target voltage (measured
on a range of RA/RB and RC/RD converters
under full output load without external filters).
The use of external filters and additional input
or output capacitance will slow this reaction
time. It is therefore left to the designer todecide on the predominant factors important
for their circuit: settling time or noise
performance.

Isolation Capacitanceand Leakage Current
The isolation barrier within the DC-DC
converter has a capacitance, which is ameasure of the coupling between input andoutput circuits. Providing this is the largest
coupling source, a calculation of the leakage
current between input and output circuits canAssuming we have a known isolation capacitance (Cis - refer to datasheet) and a known
frequency for either the noise or test signal,then the expected leakage current (iL) between
input and output circuits can be calculated
from the impedance.

Zf = ___1___
j 2 π C is
For an RB-0505D, the isolation capacitance is
18pF, hence the isolation impedance to a 50Hz
test signal is:
Z50 = ___1_______ = 177 M Ω
j 2 π 50 18 pf
If using a test voltage of 1kVrms, the leakage
current is:iL = Vtest = _1000V_ = 5.65 µA
177 M ΩZf
It can be easily observed from these simple
equations that the higher the test or noisevoltage, the larger the leakage current, also thelower the isolation capacitance, the lower the
leakage current. Hence for low leakage
current, high noise immunity designs, highisolation DC-DC converters should be selectedwith an appropriate low isolation capacitance.

RECOM converters with Power Limiting
Overload Protection

RECOM converters with Hiccup Overload
Protection

RY-P, R1Z, R0.25Z, RSO, RS, RW2, RS3,
RW-S, RW-D, REC3, REC3.5, REC5, REC6,
REC7.5, REC8, REC10, REC15, Rxx-B,
RP08, RP12, RAC05-A, RAC05-B,
RAC10-A, RAC10-B, RAC15-A, RAC15-B,
RAC20-A, RAC20-B, RAC30-A, RAC40-A,
RAC40-B

RP10-E, RP12-SOF, RP15-A, RP15-F,
RP20-A, RP20-F, RP30-E, RP30-F, RP40-G,
RP60-G, RAC03-A, RAC04-A, RAC06-C,
RAC60-B

RECOM converters with Power Limiting
Overload Protection, but need diodeprotection with high capacitive loads

RECOM converters with Hiccup Overload
Protection, but can cope well with highcapacitive loads

R-78xx, R-78Bxx, R-78HBxx, R-5xxx,
R-6xxx, R-7xxx

RPP20, RPP30, RPP40, RPP40, RPP50

www.recom-international.com

2014

A-7

DC-DC Converter Applications
Application Examples
Overload Protection
Although the use of filtering will prevent
excessive current at power-on under normal
operating conditions, many of the lower costconverters have no protection against an output
circuit taking excessive power or even goingshort-circuit. When this happens, the DC-DC
converter will take a large input current to try
to supply the output. Eventually the converter
will overheat and destroy itself if this condition
is not rectified (short circuit overload durationis only for 1s on a standard unregulated part).
There are several ways to prevent overload at
the outputs destroying the DC-DC converter.
The simplest being a straight forward fuse.
Sufficient tolerance for inrush current is required
to ensure the fuse does not blow on power-on(see figure 8). Another simple scheme thatcan be applied is a circuit breaker.
There is also the potential to add someintelligence to the overload scheme by either
detecting the input current, or the output
voltage (see figure 9).
If there is an intelligent power management
system at the input, using a series resistor (inplace of the series inductor) and detecting thevoltage drop across the device to signal the
management system can be used.

A similar scheme can be used at the output todetermine the output voltage, however, if the
management system is on the input side, thesignal will need to be isolated from thecontroller to preserve the system isolation
barrier (see figure 10).
There are several other current limiting techniques that can be used to detect an overload
situation, the suitability of these is left to thedesigner. The most important thing to consider
is how this information will be used. If thesystem needs to signal to a controller thelocation or module causing the overload, someform of intelligence will be needed. If the device
simply needs to switch off, a simple fuse typearrangement will be adequate.
Unregulated RECOM DC/DC converters usually
are short circuit protected only for a short time,e.g. 1 second.

VIN

By option they can be continous short circuit
protected (option /P), then their design is able
to withstand the high output current in a shortcircuit situation without any need for extra circuit protection.
All Recom DC-DC converters which include
an internal linear regulator have a thermal
overload shut-down condition which protects
these devices from excessive over-load.
If this condition is to be used to signal a power
management system, the most suitablearrangement is the output voltage detector(see figure 10a), since this will fall to near zeroon shut-down. Wide input range regulated
converters offer overload protection / shortcircuit protection via an internal circuit thatinterfers with the primary oscillator so theswitching is regulated back in situations ofoverload or output short circuit.

FUSE

DC

CIN

DC

GND

Figure 8: Simple Overload Protection

Rin

Vcc

DC
DC

Vout
GND

a) Series Resistor for Input Current Measurement
Ilimit

Vcc

DC

R1

DC
Rgnd

R2

GND

b) Ground Current Monitor

Choose current limit (ILIMIT)
and ground resistor (RGND) sothat : 0.7V = RGND x ILIMIT.

Figure 9: Input Monitored Overload Protection

A-8

2014

www.recom-international.com

DC-DC Converter Applications
Input Voltage
Drop-Out (brown-outs)
When the input voltage drops, or is momentarily
removed, the output circuit would suffer similar
voltage drops. For short period input voltage
drops, such as when other connected circuits
have an instantaneous current demand, or
devices are plugged in or removed from the
supply rail while 'hot', a simple diode-capacitor
arrangement can prevent the output circuitfrom being effected.

Opto-Isolated Power Good / Overload Detector(On overload +VO falls and the LED switches off, the VOL. line is then pulled high.)
Figure 10 : Ouput Monitored Overload Protection

LIN

ZDX60

DC

VIN

Output Circuit

47pf

DC

GND

The circuit uses a diode feed to a large reservoir
capacitor (typically 47µF electrolytic), which
provides a short term reserve current source
for the converter, the diode blocking othercircuits from draining the capacitor over the
supply rail. When combined with an in-line
inductor this can also be used to give very
good filtering. The diode volt drop needs to beconsidered in the power supply line undernormal supply conditions. A low drop Schottky
diode is recommended (see figure 11).

No Load Over Voltage Lock-Out
Unregulated DC-DC converters are expected to
be under a minimum of 10% load, hence
below this load level the output voltage is
undefined. In certain circuits this could be apotential problem.

Figure 11 : Input Voltage Drop-out

The easiest way to ensure the output voltage
remains within a specified tolerance, is to add
external resistors, so that there is always aminimum 10% loading on the device (seefigure 12). This is rather inefficient in that 10%of the power is always being taken by this load,hence only 90% is available to the additional
circuitry.
Zener diodes on the output are another simple
method. It is recommended that these be usedwith a series resistor or inductor, as when the
Zener action occurs, a large current surge may
induce signal noise into the system.

Figure 12: No Load over Voltage Lock-Out

Long Distance Supply Lines
RB-0512D

RO-2405

DC

Vin
GND

Cable

DC

DC
DC

Target Circuit

When the supply is transmitted via a cable,
there are several reasons why using an isolated
DC-DC converter is good design practice (seefigure 13). The noise pick up and EMC
susceptibility of a cable is high compared to a
pcb track. By isolating the cable via a DC-DC
converter at either end, any cable pick-up willappear as common mode noise and should be
self-cancelling at the converters.

Figure 13: Long Distance Power Transfer

www.recom-international.com

2014

A-9

DC-DC Converter Applications
Another reason to use converter pairs is to
reduce the cable power loss is by using a highvoltage, low current power transfer through thecable and reconverting at the terminating
circuit. This will also reduce noise and EMC
susceptibility, since the noise voltage required
to affect the rail is also raised.
For example, compare a system having a 5V
supply and requiring a 5V, 500mW output at aremote circuit. Assume the connecting cablehas a 100 Ohm resistance. Using an RO-0505
to convert the power at either end of the cable,with a 100mA current, the cable will lose 1W(I2R) of power. The RO would not be suitable,
since this is its total power delivery; hence
there is no power available for the terminating
circuit. Using a RB-0512D to generate 24V anda RO-2405S to regenerate the 5V, only a 21
mA supply is required through the cable, acable loss of only 44mW.
Some high power, low output voltage circuits
experience significant voltage drops even along
the short tracks on a circuit board. The
Powerline RP40 and RP60 and the Innoline
R-5xxxA converters feature a senseconnection which can automaticallycompensate for voltage losses in a circuit (seeFigure 13a). The sense inputs are used by theinternal regulator in the converters so that theset output voltage is measured at the load
rather than on the output pins of the converter.

RP60-xxxxS

DC +Sense
DC
Pre- and Post Regulation
The usefulness of many DC-DC converters canbe enhanced by pre- or post-regulation.
The usual input voltage range of a DC-DC
converter is either fixed, 2:1 or 4:1 dependingon the converter technology used inside thedevice. Switching regulators have typically amuch wider input voltage range - up to 8:1,
but do not have the advantage of the DC-DC
converter’s galvanic isolation. By combining
the two techniques and using a switchingregulator as a pre-regulator, an ultra-widerange, isolated DC-DC converter supply can bebuilt (see Figure 15a)
Vcc = 9~72VDC
R-78HB05-0.5

LCD Display Bias

DC

-24V

-Sense-Vo

Post regulation is useful to combine theadvantages of a linear regulator’s low noise
output with the ability of a DC-DC converter toboost a lower input voltage to a higher output
voltage.
Vcc = 5V
RB-053.3D

DC
DC

GND

+6.6V
+Vo

7805
LDO

+5V
100n

2µ2
-Vo

(Optional Link)<5µV
Low Noise
Regulated
5V Output
0V

Figure 15b: Post-Regulation Example

RI-0505SDC+5V @ 400mA

Isolated VoutIn this example, a low cost RB unregulated
converter is used to boost a 5V supply up to
6.6V so that a low drop out linear regulator can
produce a low noise, regulated 5V output.

EIA-232 Interface

GND
Figure 15a: Pre-Regulation Example

RO-0524S

DC

Load

Figure 13a: Using Sense Inputs to Compensate for Voltage Drops in the Connections to the LoadDCA LCD display typically requires a positive or
negative 24V supply to bias the crystal. The
RO-0524S converter was designed specificallyfor this application. Having an isolated OV output, this device can be configured as a +24V
supply by connecting this to the GND input, ora –24V supply by connecting the +Vo output to
GND (see figure 14).

+Vo

LiquidCrystal
Display

In a mains powered PC often several supply
rails are available to power a RS232 interface.
However, battery operated PC’s or remoteequipment having a RS232 interface added
later, or as an option, may not have the supply
rails to power a RS232 interface. Using a
RB-0512S is a simple single chip solution,
allowing a fully EIA-232 compatible interface
to be implemented from a single 5V supply rail,and only two additional components (see figure
16a).

(up to 42mA)

Figure 14: LCD Display Bias

A-10

2014

www.recom-international.com

DC-DC Converter Applications
3V/5V Logic Mixed Supply Rails+12V
EIA-232 Port

VCC

5V

VDD

DCD

RB-0512D

DB9S Connector

DSR

+VO

RX

DC

OV

RTS
TX

-VO

CTS

DC

DTR
GND

RI

There is now another option, mixed logic
functions running from separate supply rails. A
single 3.3V line can be combined with a rangeof DC-DC converters from Recom, to generate
voltage levels to run virtually any standard logic
or interface IC.

SN75C185

The Recom range includes dual output partsfor powering analogue bipolar and amplifierfunctions (RB series), as well a single output
function for localised logic functions (RM, RN or
RNM series). A typical example might be a
RS232 interface circuit in a laptop PC using a
3.3V interface chip (such as the LT1330),
which accepts 3.3V logic signals but requires
a 5V supply (see figure 16b). Recom has anothervariation on this theme and has developed two
5V to 3.3V step down DC-DC converters(RNM-053.3S and R0-053.3S). These havebeen designed to allow existing systems tostart incorporating available 3.3V l.C.’s
without having to redesign their power
supply.

Figure 16a: Optimised RS232 Interface

3.3VCC

RNM-3.305S
3

1

8

DC
DC

+5V

7

OV

GND

GND
VCC

1µF

100nF

-V

+V
1

2

28

3

26

4

27

TX1

14
25

5

TX1

RX1

24

6

RX1

+
3.3V

This is particularly important when trying to
reduce the overall power demand of a system,
but not having available all of the functions at
the 3.3V supply.

+

220nF

3.3V Logic

There has been a lot of attention given to new
l.C.'s and logic functions operating at what is
rapidly emerging as the standard supply levelfor notebook and palmtop computers. The 3.3V
supply is also gaining rapid acceptance as thedefactostandard
for
personal
telecommunications, however, not all circuit
functions required are currently available in a
3.3V powered IC. The system designer
therefore has previously had only two options
available; use standard 5V logic or wait until
the required parts are available in a 3.3V form,
neither being entirely satisfactory and thelatter possibly resulting in lost market share.

200nF

RS232

The main application for this range of devices
are system designers, who want to provide
some functionality that requires a higher
voltage than is available from the supply rail, orfor a single localised function. Using a fully
isolated supply is particularly useful in interfacefunctions and systems maintaining separate
analogue and digital ground lines.

17

LT1330

GND

Figure 16b: RS232 Interface with 3V Logic

www.recom-international.com

2014

A-11

DC-DC Converter Applications
Isolated Data Acquisition System
Any active system requiring isolation will need a DC-DC converter to provide the power transfer for the isolated circuit. In a data acquisition circuit
there is also the need for low noise on the supply line; hence good filtering is required. The circuit shown (see figure 17) provides a very highvoltage isolation barrier by using an RH converter to provide the power isolation and opto isolators for the data isolation. An overall system isolationof 2.5kV is achieved.
EMC Considerations: When used for isolating a local power supply and incorporating the appropriate filter circuits as illustrated in Fig. 17), DC-DC
converters can present simple elegant solutions to many EMC power supply problems. The range of fixed frequency DC-DC converters isparticularly suitable for use in EMC problem situations, as the stable fixed switching frequency gives easily characterised and easily filtered output.
The following notes give suggestions to avoid common EMC problems in power supply circuits.
5V
4K7

Data

Opto Isolators

RH-0505

1K2

5V

5V Logic Circuit

Data
CS

4K7

5V

CS
1K2

4K7

Status

VCC

+5V

1K2

ZN509
CLK

+5V
CLK

Vref

Status

47µH

+5V

AIN

1K2

DC
DC

+5V
1µF

470vF

GND

4K7

1K2

SFH610Figure 17: Isolated Serial ADC System

Power Supply Considerations

VCC

PSU

CCT1

● Eliminate loops in supply lines (see figure 18).
● Decouple supply lines at local boundaries (use LC filters with low Q,

8

CCT2

see figure 19).
● Place high speed sections close to the power line input, slow

speed sections furthest away (reduces power plane transients, see
figure 20).
● Isolate individual systems where possible (especially analogue
and digital systems) on both power supply and signal lines (see figure 21).
An isolated DC-DC converter can provide a significant benefit to help
reduce susceptibility and conducted emission due to the isolation ofboth power rail and ground from the system supply. Recom primarily
uses toroidal transformers in our DC-DC converters and as such they
have negligible radiated EMI, but all DC-DC converters are switching
devices and as such will have a characteristic switching frequency,
which may need some additional filtering.

GND

VCC

PSU

CCT1

3

CCT2

GND

Interpretation of DC-DC Converter EMC Data

Figure 18: Eliminate Loops in Supply Line

Electromagnetic compatibility (EMC) of electrical and electronic products
is a measure of electrical pollution. Throughout the world there are
increasing statutory and regulatory requirements to demonstrate the
EMC of end products. In Europe the EC directive 89/336/EEC requiresthat any product sold after 1 January 1996 complies with a series of
EMC limits, otherwise the product will be prohibited from sale within
the EEC and the seller could be prosecuted and fined.
Although DC-DC converters are generally exempt from EMC restrictions
on the grounds that they are components, it is the belief of Recom that
information on the EMC of these components can help designers planahead so that their end products can meet the relevant statutory EMC
requirements. It must be remembered however, that a DC-DC converter
is unlikely to be the only com-ponent in the power supply chain, hence
the information quoted needs interpretation by the circuit designer todetermine its impact on the final EMC performance of their system.

VCC

CCT1

CCT2

GND

Figure 19: Decouple Supply Lines at Local Boundaries

A-12

2014

www.recom-international.com

DC-DC Converter Applications
Hence, the EC directive covers the frequency
spectrum 150kHz to 1GHz, but as two
separate and distinct modes of transmission.
Local

P
S
U

Power Input

High Speed
Circuit

DC Circuit

The Recom range of DC-DC converters feature
toroidal transformers. These have been tested
and proved to have negligible radiated noise.
The low radiated noise is primarily due totoroidal shaped transformers maintaining themagnetic flux within the core, hence nomagnetic flux is radiated by design. Due to the
exceptionally low value of radiated emission,
only conducted emissions are quoted.

CCT2

Conducted emissions are measured on the
input DC supply line. Unfortunately nostandards exist for DC supplies, as moststandards cover mains connected equipment.
This poses two problems for a DC supplied
device, firstly no standard limits can be directly
applied, since the DC supplied device does
not directly connect to the mains, also allreference material uses the earth-ground asa reference point. In a DC system often the OV
is the reference, however, for EMC purposes, it
is probably more effective to maintain the earth
as the reference, since this is likely to be thereference that the shielding is connected to.
Consequently all measurements quoted arereferenced to the mains borne earth.

Low Speed
CircuitMedium Speed
Circuit

FilterFigure 20: Place High Spead Circuit Close to PSU

VCC

DC

DC

CCT1

DC

DC

GND

Figure 21 : Isolate Individual Systems

Line Impedance Stabilisation
Network (LISN)
Power Supply

50Ω
Termination

–

LISN

DC

Load

DC
+

LISN

To Spectrum Analyser

Figure 22: Filtered Supply to DC-DC Converter

The notes given here are aimed at helping
the designer interpret the effect the DC-DC
converter will have on the EMC of their end
product, by describing the methods and rationale for the measurements made. Where
possible CISPR and EN standards have beenused to determine the noise spectra of thecomponents, however, all of the standards
reference to mains powered equipment andinterpretation of these specifications isnecessary to examine DC supplied devices.

www.recom-international.com

Conducted andRadiated Emissions
There are basically two types of emissions
covered by the EC directive on EMC: radiatedand conducted. Conducted emissions arethose transmitted over wire connecting circuits
together and covers the frequency spectrum
150kHz to 30MHz. Radiated are those emissions
transmitted via electromagnetic waves in air
and cover the frequency spectrum 30MHz to
1GHz.

2014

It is necessary to ensure that any
measure-ment of noise is from the device
under test (DUT) and not from the supply to thisdevice. In mains connected circuits this isimportant and the mains has to be filtered prior
to supply to the DUT. The same approach has
been used in the testing of DC-DC converters
and the DC supply to the converter was filtered,to ensure that no noise from the PSU as
present at the measuring instrument.
A line impedance stabilisation network (LISN)
conforming to CISPR 16 specification isconnected to both positive and negative supply
rails and referenced to mains earth (see figure22). The measurements are all taken from thepositive supply rail, with the negative rail
measurement point terminated with 50 Ohm toimpedance match the measurement channels.

A-13

DC-DC Converter Applications
2

100
Conducted Emission (dBuV)

these arise from the fundamental switchingfrequency and its harmonics (odd line spectra)
and the full rectified spectra, at twice thefundamental switching frequency (even line
spectra). Quasi-resonant converters, such as
the Recom range, have square wave switching
waveforms, this produces lower ripple and ahigher efficiency than soft switching devices,
but has the drawback of having a relatively
large spectrum of harmonics.

4
1

80

8

6

12

10
3

60

5

7

9

11
13

40
20
0
0

100

300

200

400

500

Frequency (kHz)
Figure 23: Individual Line Spectra

5040Frequency (kHz)

30
20
10
0

0

2

4

6

8

10

12

14

Input Voltage (V)Figure 24: Frequency Voltage Dependency

The EC regulations for conducted interference
covers the bandwidth 150kHz to 30MHz.
Considering a converter with a 100kHz nominal
switching frequency, this would exhibit 299
individual line spectra. There will also be avariation of absolute switching frequency withproduction variation, hence a part with a 90kHz
nominal frequency would have an additional
33 lines over the entire 30MHz bandwidth.
Absolute input voltage also produces slightvariation of switching frequency (see figure24). Hence, to give a general level of
conducted noise, we have used a 100kHz
resolution bandwidth (RBW) to examine thespectra in the data sheets. This wide RBW
gives a maximum level over all the peaks,
rather than the individual line spectra. This iseasier to read as well as automaticallycompensating for variances in switchingfrequency due to production variation ordifferences in absolute input voltage (seefigure 25).

Conducted Emission (dBuV)

100

The conducted emissions are measured underfull load conditions in all cases. Under lower
loads the emission levels do fall, hence full load
is the worst case condition for conducted line
noise.

80
60
40
20
0
100kHz

1MHz

10MHz

100MHzFrequency

Econoline converters will meet therequirements for FCC / EN55022 Class A andClass B limits for conducted and radiatedemissions with the addition of an external filter.

Figure 25 : V Spectrum

ShieldingAt all times the DUT, LlSN’s and all cables
connecting any measurement equipment,loads and supply lines are shielded. The
shielding is to prevent possible pick-up on
cables and DUT from external EMC sources(e.g. other equipment close by). The shielding
is referenced to mains earth (see figure 22).

Line Spectra of DC-DC Converters
All DC-DC converters are switching devices,

A-14

Econoline Filters for Conducted
and Radiated Emissions

hence, will have a frequency spectra.
Fixed input DC-DC converters have fixedswitching frequency, for example the RC/RD
range of converters has a typical switchingfrequency of 50kHz. This gives a stable andpredictable noise spectrum regardless of loadconditions.

The following filter circuit suggestions are
based on EMC tests carried out in an EMC test
facility on single converters. Different
component values or filter configurations may
be required if several converters share acommon supply, if different types of converter
are used together or if the supply voltage orload is not placed close to the converters.

If we examine the noise spectrum closely (seefigure 23) we can see several distinct peaks,

2014

www.recom-international.com

DC-DC Converter Applications
Econoline EMC Filter Suggestions: Low Power Regulated and Unregulated Converters
For R1S, R2S: see Datasheet
EN55022 Class A(Omit C1, L1 and C3)
RM, RSS, RSD, RNM,ROM,RO, RBM,RB,RE.RK, RH, RN,
RTS, RTD, RI, RD, RKZ,RJZ,
RZ, RSZ, RY
C2=3.3µF

L1
Input

+

+

C1

C2

Output

RP, RxxPxx, RU, RxxP2xx,
RUZ, RV
C2=10µF

C3

EN55022 Class B

EN55022 Class A

EN55022 Class B

RM, RSS, RSD, RNM,ROM, RO,
RBM,RB,RE.RK, RH, RN, RTS, RTD,
RI, RD, RKZ,RJZ, RZ, RSZ, RY
C1=10µF, L1 = 470µH, C2=4.7µF,
C3 = 2.2nF(omit C3)

RS0, RS, RW2
RS3, RW-S, RW-D, REC3-R
C1=10µF, L1 = 1mH, C2=20µF,
C3 = 2.2nF

RS0, RS, RW2
RS3, RW-S, RW-D, REC3-R
C1=10µF, L1 = 1mH, C2=10µF

All capacitors are MLCC
RP, RxxPxx, RU, RxxP2xx, RUZ, RV
C1=10µF, L1 = 470µH, C2=10µF,
C3 = 2.2nF

Recommended Inductors:
WE 7447471471 470µH
WE 7447471102 1000µH or
WE 7687709102 1000µH

Econoline EMC Filter Suggestion: 3W - 15W Regulated Converters
EN55022 Class B
2:1 and 4:1 REC3-REC08
Converters:
CMC= 7448640395 820µH

Input

+

+

C1

C2

CMC

2:1 and 4:1 REC10-REC15
Converters:
CMC= 7446723001 1200µH
C3=C4=3.3nF
2:1 and 4:1 REC3-REC7.5
C1=10µF, C2=15µF,
C3=2.2nF
REC08-05xx:
C1= C2 = 22µF
REC08/10/15-12xx:
C1=C2=10µF
REC08/10/15-24xx:
C1=C2=4.7µF
REC08/10/15-48xx:
C1=C2 =2.2µF

C3

Input

+

+

C1

C2

www.recom-international.com

Dual
OutputCMC
C3"A" Pinning
Single Output

C1

For details of common mode
chokes refer to Powerline
application notes section

SingleOutput

C3

4

3

1

2

C2

GroundPlane

Bottom View

CMC
2014

A-15

DC-DC Converter Applications

Figure 26: Typical Switching Frequency vs. Temperature

Temperature Performance

Surface Mount DC-DC Converters

The temperature performance of the DC-DC
converters detailed in this book is always better
than the quoted operating temperature range.
The main reason for being conservative on theoperating temperature range is the difficulty ofaccurately specifying parametric performanceoutside this temperature range.

Production Guideline Application Note
The introduction by Recom of a new andinnovative method of encapsulating hybrid DCDC converters in a transfer moulded (TM)epoxy molding compound plastic has enabled
a new range of surface mount (SMD) DC-DC
converters to be brought to market, which
addresses the component placement withSOIC style handling.

There are some limiting factors which provide
physical barriers to performance, such as theCurie temperature of the core material used in
the DC-DC converter (the lowest Curie
temperature material in use at Recom is
125°C). Ceramic capacitors are used almost
exclusively in the DC-DC converters becauseof their high reliability and extended life
properties, however, the absolute capacity ofthese can fall when the temperature rises
above 85°C (i.e. the ripple will increase). Other
considerations are the power dissipation within
the active switching components, althoughthese have a very high temperature rating.
Their current carrying capacity derates astemperature exceeds 100°C.
Therefore this allows the DC-DC converters
to be used above their specified operating
temperature, providing the derating of power
delivery given in the specification is adhered
to. Components operating outside the quoted
operating temperature range cannot be
expected to exhibit the same parametricperformance that is quoted in the specification.
An indication of the stability of a device can beobtained from the change in its operating
frequency, as the temperature is varied (seefigure 26). A typical value for the frequency
variation with temperature is 0.5% per °C, a
very low value compared to other commercial
parts. This illustrates the ease of filtering ofRecom DC-DC converters, since the frequency
is so stable across load and temperature ranges.

A-16

With any new component there are of course
new lessons to be learned with the mounting
technology. With the Recom SMD DC-DC
converters, the lessons are not new as such,but may require different production
techniques in certain applications.
Component Materials
Recom SMD converters are manufactured in aslightly different way than the through-hole
converters. Instead of potting the PCB board
inside a plastic case with conventional epoxy
the whole package is molded around the PCB
board with epoxy molding compound plastic.
Open frame SMD parts have no moulding
compound and the case (when fitted) is
provided purely to allow the pick-amd-placemachine to be able to grip the part and toprovide a surface for the part number anddatecode. As the parts are nor encapsulated,
they have more freedom to expand andcontract which makes them ideal for vapour
phase reflow processes and allows greater
flexibility in the termperature profile.
All materials used in RECOM lead-free products
are ROHS compliant, thus the total amountof the restricted materials (lead, mercury,cadmium, hexavalent chromium, PBBs and
PBDEs) are below the prescribed limits.
Detailed chemical analysis reports are available.

2014

Component Placement
Recom SMD DC-DC converters are designed
to be handled by placement machines in asimilar way to standard SOIC packages. The
parts are available either in tubes (sticks) or inreels. The parts can therefore be placed using
machines with either vibrational shuttle, gravity
feeders, or reel feeders.The vacuum nozzle forpicking and placing the components can be thesame as used for a standard 14 pin or 18 pin
SOIC (typically a 5 mm diameter nozzle). An
increase in vacuum pressure may bebeneficial, due to the heavier weight of thehybrid compared to a standard SOIC part (atypical 14 pin SOIC weighs 0.1g, the Recom

12.00

8

5

1 2

4

1.20

Top View

1.80

SMD DC-DC converter weighs 1.5 ~ 2,7g).
It is advisable to consult your machine supplieron the best choice of vacuum nozzle if in doubt.
If placing these components by hand, handle
the components only by the central body area
where there are no component pins.
Component Alignment
The components can be aligned by either
optical recognition or manual alignment. If
using manual alignment it should be ensured
that the tweezers press on the component
body and not on the pins. The components
themselves are symmetrical along their axis,
hence relatively easy to align using either
method.
Solder Pad Design
The Recom SMD DC-DC converters aredesigned on a pin pitch of 2,54mm (0.1") with
1,20 mm pad widths and 1,80 mm pad
lengths.
This allows pads from one part to be usedwithin a PCB CAD package for forming the padlayouts for other SMD converters. These pads
are wider than many standard SOIC pad sizes(0.64mm) and CAD packages may notaccommodate these pins with a standard SOIC
pad pattern. It should be remembered thatthese components are power supply devices
and as such need broader pads and thicker
component leads to minimise resistive losses
within the interconnects.

www.recom-international.com

DC-DC Converter Applications
The adhesive prevents the SMD parts being”washed off“ in a wave solder, and being”vibrated off“ due to handling on a double
sided SMD board.

Lead-free Recommended Soldering Profile (SMD parts)
300

10-30smin. 300s

Temperature (°C)

250

(245°C)

200
150

Pre - Heat

100
50

50

100

200

150

250

300

350

400

450

500

Time (seconds)

Lead-free Recommended Soldering Profile (Through hole parts)
Double Wave

340
320
300

3 - 5 seconds

Temperature (°C)

280
260
240
220

Forced Cooling
60°C/s Min.

100°C ~ 150°C Max.

200
180
160
140
120
100
80
60
40
20
0

Natural CoolingEnter Wave

Pre - Heat
0

10

20

30

40

50

60

70

80

Time (seconds)

90

100

110

120

Notes: 1. The wave solder profile is measured on lead temperature.
2. Need to keep the solder parts internal temperature less than about 210°C

Solder Reflow Profile
RECOM’s SMD converters are designed towithstand a maximum reflow temperature of
245°C (for max. 30seconds) in accordancewith JEDEC STD-020C. If multiple reflow
profiles are to be used (i.e. the part is topassthrough several reflow ovens), it isrecommended that lower ramp rates be usedthan the maximum specified in JEDEC STD020C. Continual thermal cycling to thisprofile could cause material fatigue, if morethan 3 maximum ramp cycles are used.
In general these parts will exceed the re-flow
capability of most IC and passive components
on a PCB and should prove the most thermallyinsensitive component to the reflow conditions
www.recom-international.com

Recommended Solder Reflow Profile:
The following 2 graphs show the typicalrecommended solder reflow profiles for SMD
and through-hole ROHS compliant converters.
The exact values of the profile’s peak and its
maximum allowed duration is also given in thedatasheet of each converter.
Adhesive Requirements
If SM surface mount components are going to
be wave soldered (i.e. in a mixed through holeand SMD PCB) or are to be mounted on bothsides of a PCB, then it is necessary to use anadhesive to fix them to the board prior to
reflow.
2014

As mentioned previously, the Recom range of
SMD DC-DC converters are heavier thanstandard SOIC devices. The heavier weight is adue to their size (volume) and internal hybrid
construction. Consequently the parts place alarger than usual stress on their solder joints
and leads if these are the only method of
attachment. Using an adhesive between
component body and PCB can reduce thisstress considerably. If the final system is to be
subjected to shock and vibration testing, thenusing adhesive attachment is essential toensure the parts pass these environmental
tests.
The Recom SMD DC-DC converters all have astand-off beneath the component for theapplication of adhesive to be placed, without
interfering with the siting of the component.
The method of adhesive dispensing and curing,plus requirements for environmental test andin-service replacement will determine suitabilityof adhesives rather than the component itself.
However, having a thermoset plastic body,
thermoset epoxy adhesive bonding between
board and component is the recommended
adhesive chemistry.
If the reflow stage is also to be used as a curefor a heat cure adhesive, then the component
is likely to undergo high horizontal accelerationand deceleration during the pick and place
operation. The adhesive must be sufficiently
strong in its uncured (green) state, in order tokeep the component accurately placed.
Adhesive Placement
The parts are fully compatible with the 3 main
methods of adhesive dispensing; pin transfer,
printing and dispensing. The method of placing
adhesive will depend on the available processes
in the production line and the reason for using
adhesive attachment. For example, if the partis on a mixed though-hole and SMD board,adhesive will have to be placed and cured prior
to reflow. If using a SMD only board and heat
cure adhesive, the reflow may be used as thecure stage. If requiring adhesive for shockand vibration, but using a conformal coat, thenit may be possible to avoid a separate
adhesive alltogether, and the coating alone
provides the mechanical restraint on thecomponent body.

A-17

DC-DC Converter Applications
Patterns for dispensing or printing adhesive are
given for automatic lines. If dispensing
manually after placement the patterns for UV
cure are easily repeated using a manualsyringe (even if using heat cure adhesive).If
dispensing manually, dot height and size are notas important, and the ad-hesive should beapplied after the components have been
reflowed. When dispensing after reflow, a chipunderfill formulation adhesive would be thepreferred choice. These types 'wick' under thecomponent body and offer a good all roundadhesion from a single dispensed dot.
The patterns allow for the process spread of
the stand-off on the component, but do notaccount for the thickness of the PCB tracks.
If thick PCB tracks are to be used, a grounded
copper strip should be laid beneath the centreof the component (care should be exercised tomaintain isolation barrier limits). The adhesive
should not retard the pins reaching their solder
pads during placement of the part, hence low
viscosity adhesive is recommended.
The height of the adhesive dot, its viscosity andslumping properties are critical. The dot mustbe high enough to bridge the gap between
board surface and component, but low enoughnot to slump and spread, or be squeezed by
the component, and so contaminate the solder
pads.
If wishing to use a greater number of dots ofsmaller diameter (common for pin transfer
methods), the dot pattern can be changed, byfollowing a few simple guidelines. As thenumber of dots is doubled their diametershould be halved and centres should be atleast twice the printed diameter from eachother, but the dot height should remain at
0.4mm. The printed dot should always be
positioned by at least its diameter from thenearest edge of the body to the edge of the dot.
The number of dots is not important, provided good contact between adhesive and bodycan be guaranteed, but a minimum of two dots
is recommended.
Cleaning
The thermoset plastic encapsulating material
used for the Recom range of surface mount
DC-DC converters is not fully hermeticallysealed. As with all plastic encapsulated active
devices, strongly reactive agents in hostileenvironments can attack the material and theinternal parts, hence cleaning is recommended
in inert solutions (e.g. alcohol or water based

A-18

solvents) and at room temperature in an inert
atmospheres (e.g. air or nitrogen).
A batch or linear aqueous cleaning process
would be the preferred method of cleaning
using a deionised water solution.

Vapour Phase Reflow Soldering
Vapour phase soldering is a still upcoming
soldering practice; therefore there are nostandard temperature profiles available.
Principally, the Lead-free Soldering Profile
recommended by RECOM can be used forvapour phase soldering. RECOM has tested
large quantities of 8-pin and 10-pin SMD
converters and recommends as an absolute
maximum condition 240°C for 90s dwell time.
In standard applications with small sizedcomponents on a pcb, 230°C and shorter
dwell times will still deliver good results.
After discussions with various contract
manufacturers, we recommended that thetemperature gradients used during preheat andcooling phases are between 0.5°K/s up to
3°K/s.
Other form factors than 8-pin or 10-pin SMDpackages have not been fully tested undervapour phase conditions. Please contact
RECOM in this case.

Custom DC-DC Converters
In addition to the standard ranges shown in thisdata book, Recom have the capability to
produce custom DC-DC converters designed
to your specific requirements. In general, theparts can be rapidly designed using computer
based CAD tools to meet any input or output
voltage requirements within the ranges ofRecom standard products (i.e. up to 48V ateither input or output). Prototype samples canalso be produced in short timescales.
Custom parts can be designed to yourspecification, or where the part fits within astandard series, the generic series specification can be used. All custom parts receive thesame stringent testing, inspection and quality
procedures, as standard products. However
there is a minimum order quantity as the
additional documentation and administrative
tasks must be covered in terms of costs.
A general figure for this MOQ can be around
3000pcs of low wattage converters(0,25W ~ 2W), 1000pcs medium sized
wattage (2W~15W) and 500pcs for higher
wattages (> 20W).

2014

Recom custom parts are used in many
applications, which are very specific to theindividual customer, however, some typicalexamples are:
● ECL Logic driver● Multiple cell battery configurations● Telecommunications line equipment● Marine apparatus● Automotive electronics● LCD display power circuitry● Board level instrumentation systems

To discuss your custom DC-DC converter
requirements, please contact Recom technicalsupport desk or your local distributor.

Tin Whisker Mitigation
The use of pure tin coating has caused
considerable customer concern about thepossibility of tin whisker formation. Although itis the opinion of Recom that the risks ofconverter failure due to tin whisker formation
are vanishingly small (the only actual recorded
failures due to tin whiskers were in exceptional
environments such as deep space or as acontributary factor to corona discharge
flashover in a UHV transformer), we haveundertaken tin whisker mitigation proceduresas recommended by Jedec in their JP002
guidelines.

Through Hole Devices:
The pins used in all of our through-hole
converters are made of hard silver-copper
alloy. The pins are then nickel underplated to
0.5µm before being pure tin electroplated to
6µm thickness. This thickness of overplating is
a compromise between reasonable
manufacturing costs and having a thickenough coating to impair tin whisker formation.
The surface is not ‘brightened’, also to
mitigate tin whisker formation.
Finally the pins are annealed according to JIS
C3101. This reduces any residual forming
stresses, which is one of the other potential
causes of tin whisker formation

Surface Mount Devices:
The carrier frames used in our SMD converters are made from DF42N nickel alloy which
is pure tin plated. The pins are hot dipped in
Sn-Ag-Cu solder just before injection molding.
Hot dipping with SnAg4 or SnAgCu is generally
an effective mitigation practice and consideredwhisker free.

www.recom-international.com

Innoline Application Notes
Contents
Innoline Application Notes●

Positive-to-Negative Converters●

EMC Considerations

R-78xx-0.5 Series

R-78Cxx-xx Series●

Soft Start Circuit

R-78Axx-0.5SMD Series

R-78HBxx-xx Series

R-78xx-1.0 Series

R-62xxP_D Series

R-78Axx-1.0SMD Series

Pos-to-Neg Circuit Ideas

R-78Bxx-1.0 Series

EMC Considerations
Although all Innoline converters are switching regulators, and contain internal high frequency oscillators, they have been designed to minimise
radiated and conducted emissions.
If the end-application is particularly sensitive to conducted interference, the following input filter can be used for all R-78, R-5xxx, R-6xxx and
R-7xxx converters.

R-78xx EMC Filter
Class B: C1=10µF MLCC, C2=10µF MLCC,
L1=56µH

Vin

L1

R-78Cxx EMC Filter

Input

Class A: C1=C2=10µF MLCC, L1=10µH

C1

C2

Vout
GND
OutputClass B: C1=22µF MLCC, C2=10µF MLCC,
L1=56µH

Output Soft Start
Innoline converters with Vadj pins (R-78Axx-xxSMD, R-5xxx, R-6xxx and R-7xxx families) can be fitted with an external circuit to create an output
soft start. Any general purpose PNP transistor and diode can be used for TR1 and D1 and typical values for R1 = 100K and C1 = 10µF.

+Vin

Vcc

+Vout

Ctrl GND Vadj
On/Off

R1

D1

TR1
C1

GND

www.recom-international.com

2014

A-19

Innoline Application Notes
Positive to Negative Converters
Switching Regulators can also be used
Features ● Innoline
to convert a positive voltage into a negative
voltage

Innoline
Switching
Regulators● The standard parts can be used - only two extra

capacitors are required● Fixed and variable output voltages are available.
● Input voltage range can be lower than the output
voltage for higher output voltages

Positive-to-Negative Switching Regulators Selection Guide
Series

R-78xx-0.5
R-78AAxx-0.5SMD
R-78xx-1.0
R-78AAxx-1.0SMD
R-78Bxx-1.0

R-78Bxx-1.5
R-78HBxx-0.5

Maximum
OutputCurrent
-0.4A
-0.2A
-0.4A
-0.2A

Input Voltages
(VDC)
min.
max.
4.75 – 28,
5.0 – 26, 8.0 – 18
4.75 – 28,
5.0 – 26, 8.0 – 18

Output Voltages(VDC)

No. ofOutputs

Case

Adjustable
Vout?

-1.5, -1.8, -2.5, -3.3, -5.0,-6.5, -9.0, -12, -15-1.5, -1.8, -2.5, -3.3, -5.0,-6.5, -9.0, -12, -15

S

SIP3

No

Max
Cap.
Load
220µF

S

SMD

Yes

220µF

No

220µF

No

100µF

-1A/-0.8A/-0.6A
9 - 28, 9-26
-1.8, -2.5, -3.3, -5, -9, -12
S
SIP12
Yes
Not recommended to be used in this mode due to the reduced efficiency and higher Ripple & Noise figures.

470µF

Not recommended to be used in this mode due to the reduced input and output voltage range
Not recommended to be used in this mode due to the reduced input and output voltage range-0.6A
4.75 – 28,-1.5, -1.8, -2.5, -3.3, -5.0,
S
SIP3
-0.4A
8.0 – 28, 8.0 – 26
-6.5, -9.0,-0.3A
8.0 – 18
-12, -15
Not recommended to be used in this mode due to the reduced input and output voltage range-0.4A/-0.35A
15 – 65,-3.3, -5.0,-6.5
S
SIP3-0.3A/-0.25A/-0.2A
15 – 62, 15 – 59, 15 – 56,-9.0, -12, -15-0.2A
20 – 48-24

R-5xxxP/DA

Not recommended to be used in this mode due to the reduced input and output voltage range

R-61xxP/D

Not recommended to be used in this mode as R-78B series offer a lower cost alternative

R-62xxP/D
R-7xxxP/D
Circuit Ideas

A-20

2014

www.recom-international.com

INNOLINE

Positive to Negative Converter

DC/DC-Converter
0V

0V
+Vin

C1 and C2 are required
and should be fitted close
to the converter pins.

31

R-78Bxx-1.0

Maximum capacitive load
including C2 is 220µF

2

C1

C2
-Vout

Pin Connections
Pin #Negative
Output
1
+Vin
2
-Vout
3
GND

RECOM
R-785.0-05****

Positive
Output
+Vin
GND
+Vout

R-78xx-0.5
SeriesPositive to
Negative
Converter

1 2 3
Selection Guide
Part
Number
SIP3

Input
Range (1)(V)

OutputVoltage(V)

OutputCurrent(A)

Efficiency
Min. Vin
Max. Vin(%)(%)

External Capacitors
C1
C2*

R-781.5-0.5

4.75 – 28

-1.5

-0.4

68

67

10µF/35V

22µF/6.3V

R-781.8-0.5

4.75 – 28

-1.8

-0.4

71

70

10µF/50V

22µF/6.3V

R-782.5-0.5

4.75 – 28

-2.5

-0.4

75

76

10µF/50V

22µF/6.3V

R-783.3-0.5

4.75 – 28

-3.3

-0.4

77

80

10µF/50V

22µF/6.3V

R-785.0-0.5

4.75 – 28

-5.0

-0.4

79

84

10µF/50V

22µF/10V

R-786.5-0.5

5.0 – 26

-6.5

-0.3

81

86

10µF/50V

10µF/10V

R-789.0-0.5

8.0 – 18

-9.0

-0.2

87

89

10µF/50V

10µF/16V

R-7812-0.5

8.0 – 18

-12

-0.2

87

90

10µF/50V

10µF/25V

R-7815-0.5

8.0 – 18

-15

-0.2

87

91

10µF/50V

10µF/25V* Maximum capacitive load including C2 is 220µF

Application Example (see also Circuit Ideas at end of section)+Vin

1

R-78xx-0.5

3

+Vout

Derating-Graph(Ambient Temperature)

2

120
100

1

R-78xx-0.5

3Maximum capacitive

load ±220µF

2

C1

C2
-Vout

www.recom-international.com

2014

Output Power (%)

0V

0V

80
60
40
20
0

Safe Operating Area

-40

0

25

50

Operating Temperature (°C)

85
75
100
71

A-21

INNOLINE

Positive to Negative Converter

DC/DC-Converter
0V

0V

+Vin
C1

10

On/Off4,5

R-78AAxx0.5SMD

1,2(Referenced to-Vout)

R1

6

3,7
8,9

C1 and C2 are required
and should be fitted close
to the converter pins.

C2

Maximum capacitive load
including C2 is 220µF

R2

-Vout
Pin Connections
Pin #Negative
Output1,2+Vin
3,7,8,9
-Vout
4,5
GND
6
-Vout Adj.
10
On/Off

10 9 8 7 6

Positive
Output
+Vin
GND
+Vout
+Vout Adj.
On/Off

R-78AAxx-0.5 SMD
Positive to
Negative
Converter

RECOM
R-78Axx-0.5SMD
xxxx

1 2 3 4 5

Selection Guide
Part
Number
SIP3

Input
Range (1)(V)

OutputVoltage(V)

OutputCurrent(A)

Efficiency
Min. Vin
Max. Vin(%)(%)

External Capacitors
C1
C2

R-78AA1.5-0.5SMD

4.75 – 28

-1.5

-0.4

68

67

10µF/35V

22µF/6.3V

R-78AA1.8-0.5SMD

4.75 – 28

-1.8

-0.4

71

70

10µF/50V

22µF/6.3V

R-78AA2.5-0.5SMD

4.75 – 28

-2.5

-0.4

75

76

10µF/50V

22µF/6.3V

R-78AA3.3-0.5SMD

4.75 – 28

-3.3

-0.4

77

80

10µF/50V

22µF/6.3V

R-78AA5.0-0.5SMD

4.75 – 28

-5.0

-0.4

79

84

10µF/50V

22µF/10V

R-78AA6.5-0.5SMD

5.0 – 26

-6.5

-0.3

81

86

10µF/50V

10µF/10V

R-78AA9.0-0.5SMD

8.0 – 18

-9.0

-0.2

87

89

10µF/50V

10µF/16V

R-78AA12-0.5SMD

8.0 – 18

-12

-0.2

87

90

10µF/50V

10µF/25V

R-78AA15-0.5SMD

8.0 – 18

-15

-0.2

87

91

10µF/50V

10µF/25V* Maximum capacitive load including C2 is 220µF

Application Example (see also Circuit Ideas at end of section)
+Vin

1,2

On/Off

10

R-78A(A)xx0.5SMD
3,7
8,9

+Vout

4,5

R1

6

Maximum capacitive

load ±220µF(Ambient Temperature)

R2

0V

120
100

0V

1,2

C1
Optocoupler

10

R-78A(A)xx0.5SMD
3,7
8,9

6

Output Power (%)

Optocoupler

A-22

Derating-Graph

4,5

R1

C2

R2

-Vout

2014

80
60
40
20
0

Safe Operating Area

-40

0

25

50

Operating Temperature (°C)

85
75
100
71

www.recom-international.com

INNOLINE

R-78AAxx-0.5 SMD
Positive to Negative

DC/DC-Converter
Table 1: Adjustment Resistor Values
0.5AdcVout (nom.)

R-78AA1.8-0.5SMD
1.8Vdc

R-78AA2.5-0.5SMD
2.5Vdc

R-78AA3.3-0.5SMD
3.3Vdc

R-78AA5.0-0.5SMD
5.0Vdc

R-78AA6.5-0.5SMD
6.5Vdc

R-78AA9.0-0.5SMD
9.0Vdc

R-78AA12-0.5SMD
12.0Vdc

Vout (adj)

R1

R1

R1

R1

R1

R1

R1

-1.5 (V)

3KΩ

R2

R2

R2

R2

R2

R2

R2

200Ω

-1.8 (V)12KΩ

-2.5 (V)11.8KΩ

-3.0 (V)

4.64KΩ

44.2KΩ 88.4KΩ

17KΩ

-3.3 (V)

27KΩ

6.7KΩ

-3.6 (V)60.4KΩ

42KΩ

14KΩ

-3.9 (V)

28KΩ

58KΩ

23KΩ

-4.5 (V)

11.3kΩ

180KΩ

49KΩ

26KΩ

17KΩ

-4.9 (V)

7.15kΩ

850KΩ

77kΩ

36KΩ

24KΩ

-5.0 (V)

6.34kΩ

86kΩ

39KΩ

26KΩ

-5.1 (V)

5.9kΩ

231kΩ

97KΩ

42KΩ

28KΩ

-5.5 (V)3.9kΩ

56.2kΩ

160KΩ

56KΩ

36KΩ

-6.5 (V)

14kΩ

112KΩ

63KΩ

-8.0 (V)

2.32kΩ

24.6KΩ 400KΩ

125KΩ

-9.0 (V)10.7KΩ

200KΩ

-10 (V)

4.75KΩ

54.9KΩ 345KΩ

-11 (V)

1.65KΩ

16.5KΩ 740KΩ

-12 (V)3.6KΩ

-12.6 (V)

0Ω

180KΩ

Typical Application

1,2

+

10

Vin=15VDC

R-78A(A)120.5SMD
3,7
8,9

+Vout

4,5
26k

6

+5V

100k

+7.5V

200k

+9V
+12V

-

0V
1,2

10µF

10

R-78A(A)120.5SMD
3,7
8,9

4,5

6

22µF
26k

-5V

100k

-7.5V

200k

-9V
-12V

Dual Rail Selectable Output Voltage Power Supply
www.recom-international.com

2014

-Vout
A-23

INNOLINE

Positive to Negative Converter

DC/DC-Converter
0V

0V
+Vin

1

R-78Bxx1.0 Series
Positive to
Negative
ConverterC1 and C2 are required
and should be fitted close
to the converter pins.

3

R-78Bxx-1.0

Maximum capacitive load
including C2 is 220µF

2

C1

C2
-Vout

Pin Connections
Pin #Negative
Output
1
+Vin
2
-Vout
3
GND

Positive
Output
+Vin
GND
+Vout

RECOM
R-78B5.0-1.0
****
Pb

1 2 3

Selection Guide
Part
Number
SIP3

Input
Range (1)(V)

OutputVoltage(V)

OutputCurrent(A)

Efficiency
Min. Vin
Max. Vin(%)(%)

External Capacitors
C1
C2*

R-78B1.5-1.0

4.75 – 28

-1.5

-0.6

70

68

10µF/50V

22µF/6.3V

R-78B1.8-1.0

4.75 – 28

-1.8

-0.6

72

72

10µF/50V

22µF/6.3V

R-78B2.5-1.0

4.75 – 28

-2.5

-0.6

75

77

10µF/50V

22µF/6.3V

R-78B3.3-1.0

4.75 – 28

-3.3

-0.6

77

80

10µF/50V

22µF/6.3V

R-78B5.0-1.0

6.5 – 28

-5.0

-0.6

83

85

10µF/50V

22µF/10V

R-78B6.5-1.0

8.0 – 26

-6.5

-0.4

84

87

10µF/50V

10µF/10V

R-78B9.0-1.0

8.0 – 18

-9.0

-0.4

88

89

10µF/25V

10µF/25V

R-78B12-1.0

8.0 – 18

-12

-0.3

89

90

10µF/25V

10µF/25V

R-78B15-1.0

8.0 – 18

-15

-0.3

89

91

10µF/25V

10µF/25V* Maximum capacitive load including C2 is 220µF

Application Example (see also Circuit Ideas at end of section)+Vin

1

R-78Bxx-1.0

3

2

+Vout

Derating-Graph

Maximum capacitive(Ambient Temperature)load ±220µF

1

R-78Bxx-1.0

Output Power (%)

0V

0V
3

2

C1

A-24

120
100

C2

80
60
40
20
0

Safe Operating Area

-40

0

25

50

85
75
100
71

-Vout

Operating Temperature (°C)

2014www.recom-international.com

INNOLINE

Positive to Negative Converter

DC/DC-Converter

*2
RECOM
R-78Cxx-1.0
XXXX Pb

1+Vin
C1
10µ/50V2*1
C2
10µ/50V

GND

Pin Connections
Pin #Negative
Output
1
+Vin
2
-Vout
3
GND

3

GND
-Vout
RECOM
R-78C5.0-1.0****

Positive
Output
+Vin
GND
+Vout

R-78Cxx1.0 Series
Positive to
Negative
Converter

1 2 3

Selection Guide

Part
Number
SIP3

Input
Range (1)(V)

OutputVoltage(V)

OutputCurrent(A)

Efficiency
Min. Vin
Max. Vin(%)(%)

R-78C1.8-1.0

5 – 38

-1.8

-0.8

69

70

R-78C3.3-1.0

7 – 37

-3.3

-0.8

77

80

R-78C5.0-1.0

8 – 35

-5.0

-0.7

79

83

R-78C9.0-1.0

12 – 31

-9.0

-0.6

85

87

R-78C12-1.0

15 – 28

-12

-0.5

87

89

R-78C15-1.0

18 – 25

-15

-0.5

89

90

Application Example (see also Circuit Ideas at end of section)
1

+Vin
C1

RECOM
R-78Cxx-1.0
XXXX Pb

10µF/50V

3+Vout

Derating-Graph(Ambient Temperature)2
GND (Com)

GND

*1
C2
10µF/50V

1RECOM
R-78Cxx-1.0
XXXX Pb

Output Power (%)*2
3

2
When: Vin ¹ | ±Vout |

120
100

-Vout

80
60
40
20
0

Safe Operating Area

-40

0

25

50

Operating Temperature (°C)

85
75
100
68

Dual Outputs (two converters)www.recom-international.com

2014

A-25

INNOLINE

Positive to Negative Converter

0V

0V
+Vin

C1 and C2 are required
and should be fitted close
to the converter pins.

3

1

R-78HBxx-0.5

Maximum capacitive load
including C2 is 100µF

2

C1

C2
-Vout

Pin Connections
Pin #Negative
Output
1
+Vin
2
-Vout
3
GND

Positive
Output
+Vin
GND
+Vout

RECOM

DC/DC-Converter

R-78HBxx0.5 Series
Positive to
Negative
Converter

R-78HB5.0-0.5

****

Pb

1 2 3

Selection Guide
Part
Number
SIP3

Input
Range (1)(V)

OutputVoltage(V)

OutputCurrent(A)

Efficiency
Min. Vin
Max. Vin(%)(%)

External Capacitors
C1
C2*

R-78HB3.3-0.5

15 – 65

-3.3

-0.4

78

75

1µF/100V

22µF/6.3V

R-78HB5.0-0.5

15 – 65

-5.0

-0.4

82

80

1µF/100V

22µF/10V

R-78HB6.5-0.5

15 – 65

-6.5

-0.35

84

82

1µF/100V

22µF/10V

R-78HB9.0-0.5

15 – 62

-9.0

-0.3

87

85

1µF/100V

10µF/16V

R-78HB12-0.5

15 – 59

-12

-0.25

88

86

1µF/100V

10µF/25V

R-78HB15-0.5

15 – 56

-15

-0.2

89

87

1µF/100V

10µF/25V

R-78HB24-0.5

15 – 48

-24

-0.2

89

87

1µF/100V

10µF/35V* Maximum capacitive load including C2 is 100µF

Application Example (see also Circuit Ideas)

+Vin

1

3

R-78HBxx-0.5
2+Vout
Maximum capacitive(Ambient Temperature)load ±100µF

120
100

1

Output Power (%)

0V

0V
3

R-78HBxx-0.5
2

C1

C2
-Vout

A-26

Derating-Graph

2014

80
60
40
20
0

Safe Operating Area

-40

0

25

50

Operating Temperature (°C)

85
75
100
71

www.recom-international.com

INNOLINE

Positive to Negative Converter

DC/DC-Converter
0V+Vin
On/Off(Referenced to-Vout)

R-62xxP/D
SIP12
Positive to
Negative
Converter

0V
2,3,4

C1

R-62xxP/D

1

5,6
7,8

C1 and C2 are required
and should be fitted close
to the converter pins.

9,10,
11

R1

12

C2

R2

Maximum capacitive load
including C2 is 220µF-Vout

Pin Connections
Pin #Negative
Output2,3,4+Vin
5,6,7,8-Vout
9,10,11GND
12-Vout Adj.
1
On/OffPositive
Output
+Vin
GND
+Vout
+Vout Adj.
On/Off

RECOM
R-6212P
1 2 3 4 5 6 7 8 9 10 11 12

Selection Guide
Part
Number
SIP3

Input
Range (1)(V)

OutputVoltage(V)

OutputCurrent(A)

Efficiency
Min. Vin
Max. Vin(%)(%)

External Capacitors
C1
C2*

R-621.8P/D

9 – 28-1.8 (-1.5~-3.6)

-1.0

72

65

10µF/50V

100µF/6.3V

R-622.5P/D

9 – 28-2.5 (-1.5~-4.5)

-1.0

76

72

10µF/50V

100µF/6.3V

R-623.3P/D

9 – 28-3.3 (-1.8~-6V)

-1.0

79

76

10µF/50V

100µF/10V

R-625.0P/D

9 – 28-5.0 (-1.8~-9V)

-1.0

81

80

10µF/50V

100µF/10V

R-629.0P/D

9 – 26-9.0 (-3.3~-15V)

-0.8

84

85

10µF/50V

100µF/25V

R-6212P/D

9 – 26-12 (-3.3~-15V)

-0.6

86

88

10µF/50V

100µF/25V* Maximum capacitive load including C2 is 220µF

Max output current calculation:
Internal power dissipation(1W) = Io x Vo x (1-Efficiency)
Io = 1(W) / Vo x (1-Efficiency)
Example : R-625.0P
at Vin = +9VDC, Vout=-5.0V
Efficiency = 80% (see ”Selection Guide” table)
Io = 1W / 5V x (1-0.8) = -1000mA
at Vin = +9VDC, Vout=-8.0V (with trim)
Efficiency = 80% (see ”Selection Guide” table)
Io = 1W / 8V x (1-0.8) = -625mA

Ambient Temperature (°C)

Derating

90
85
80
60
40
20
0

0.5 0.71

1.5Internal Power Dissipation (W)www.recom-international.com

2014

A-27

R-62xxP_D
Positive to Negative

INNOLINE
DC/DC-Converter
Remote On/Off Control Application Example

+Vin

2,3,4

On/Off1

R-6xxxP

R1

12

5,6
7,8

+Vout

9,10,11

100µF

R2

0V

0V
Optocoupler

2,3,4

C1

1

R-62xxP

9,10,
11

R1

12

5,6
7,8

Maximum capacitive
load ±220µF

C2

R2

Optocoupler-Vout

Table 1: Adjustment Resistor Values-1Adc

R-621.8P/D

R-622.5P/D

R-623.3P/D

R-625.0P/D

Vout (nominal)

1.8VDC

2.5VDC

3.3VDC

5VDC

Vout (adj)

R1

1.5

13.6KΩ

R2

R2

R1

R2

R1

R2

3.3KΩ

1.8

A-28

R1

8.2KΩ

3.1KΩ

820Ω

15KΩ

5.1KΩ

1.5KΩ

13KΩ

3.6KΩ

51KΩ

7.0KΩ

2.0

10KΩ

2.5

5.1KΩ

3.0

2.5KΩ

10KΩ

3.3

1.7KΩ

5.9KΩ

3.6

1.2KΩ

3.9KΩ

18KΩ

14KΩ

3.9

2.8KΩ

9.1KΩ

20KΩ

4.5

1.6KΩ

3.9KΩ

60KΩ

9.7KΩ

5.0

2.4KΩ

5.1

2.2KΩ

60KΩ

5.5

1.6KΩ

15KΩ

6.0

1.1KΩ

7.2KΩ

7.0

2.8KΩ

8.0

1.5KΩ

2014

www.recom-international.com

Positive to Negative
Circuit Ideas

INNOLINE
DC/DC-Converter
Application Examples
Negative Voltage Doubler

0V

0V
-12V
1

R-78B12-1.0

3

2

10µF/
25V

10µF/
25V

-24V @ 300mA

12V Battery Stabilisor

Vbatt =
8~18V

-Ve

12V
1

+Ve

3

R-7812-0.5
2

10µF/
25V

10µF/
25V

0V

Negative Rail Generator for Asymmetric Rails

L
N

0.1µF
RAC1012SB

C1

1R-7805-0.5

47µF/
16V
C2

+12V @ 655mA
0V

3

2

10µF/
25V

C3

C1
RAC10 AC/DC Converter

C3
C4
R-78

27.2mm

C2

C4

22µF/
10V

-5V @ -400mA

Ultra-compact low noise
regulated and protected
AC/DC dual output supply.

60mm

www.recom-international.com

2014

A-29

Powerline Application Notes
Contents
Powerline DC/DC Application
Notes

Switching Frequency●

Undervoltage Lockout Tables

Output Ripple and Noise●

Output Voltage Trim Tables●

Powerline Heat Sinks●

Common Mode Chokes for EMC

Transient Recovery Time●Powerline Definitions and Testing

Current Limiting

Introduction

Fold Back Current Limiting

Input Voltage Range

Isolation

Pi Filter

Break Down Voltage

Output Voltage Accuracy

Temperature Coefficient

Input Fuse

Voltage Balance

Ambient Temperature

Earthing

Line Regulation

Operating Temperature Range

Combining Converters

Load Regulation

Storage Temperature Range

DC Inputs

Heat Sink Dimensions

Powerline AC/DC Application
Notes

Efficiency

Common Mode Chokes for EMC
Recom offers a range of Common Mode Chokes useful for EMI Filtering to meet the requirements of EN-55022, Class B.
The component values given are suggested values and may need to be optimised to suit the application. The effectiveness of any filter
network is heavily dependent on using quality capacitors, the layout of the board and having a low impedance path to ground.
See section on filtering elsewhere in the Application Notes for more details.

Class B EMC Filter Suggestion
Standard EMC Filter

C4

Input

+

+

C1

C2

Output

100nF(fit close
to pins)

CMC

C3

A-30

2014

www.recom-international.com

Powerline DC-DC Application Notes
RP15-SO_DO and RP15-SOW_DOW Series Only

470pF/ 3kV
Vout+
L1
Input

+

+ +

C1

C2

RP15-SO_DO
Output

C3
Vout-

CMC

470pF/ 3kV

RP30-SF_DF and RP30-SF W_DFW Series Only

C4
Vout+
RP30-SF_DF
RP30-SFW_DFW
Input

+

+

+

C1

C2

C3

Trim orCommonVoutCMC-1

CMC-2
C5
C6

www.recom-international.com

2014

A-31

Powerline DC-DC Application Notes
Component Values
All capacitors MLCC (Multi Layer Ceramic Capacitor).

RP08-AVin = 12VDC nom., C1=4.7µF/50V, C2=Not Required, C3,C4=1nF/3kV, WE 7448229004 350µH
Vin = 24VDC nom., C1=6.8µF/50V, C2=Not Required, C3,C4=1nF/3kV, WE 7448229004 350µH
Vin = 48VDC nom., C1=2.2µF/100V, C2=2.2µF/100V, C3,C4=1nF/3kV, WE 7448229004 350µH

RP08-AW

Vin = 9~36VDC, C1=4.7µF/50V, C2=Not Required, C3,C4=1nF/3kV, WE 7448229004 350µH
Vin = 18~75VDC, C1=2.2µF/100V, C2=2.2µF/100V, C3,C4=1nF/3kV, WE 7448229004 350µH

RP10-E
RP12-AVin = 12VDC nom., C1=3.3µF/50V, C2=Not Required, C3,C4=1nF/2kV, WE 7448229004 350µH
Vin = 24VDC nom., C1=4.7µF/50V, C2=Not Required, C3,C4=1nF/2kV, WE 7448229004 350µH
Vin = 48VDC nom., C1=2.2µF/100V, C2=2.2µF/100V, C3,C4=1nF/2kV, WE 7448229004 350µH

RP10-EW
RP12-AW

Vin = 9~36VDC, C1=3.3µF/50V, C2=Not Required, C3,C4=1nF/2kV, WE 7448229004 350µH
Vin = 18~75VDC, C1=2.2µF/100V, C2=2.2µF/100V, C3,C4=1nF/2kV, WE 74482210002 175µH

RP15-AVin = 12VDC nom., C1=10µF/25V, C2=10µF/25V, C3,C4=470pF/2kV, WE 74482210002 175µH
Vin = 24VDC nom., C1=6.8µF/50V, C2=6.8µF/50V, C3,C4=470pF/2kV, WE 7448229004 350µH
Vin = 48VDC nom., C1=2.2µF/100V, C2=2.2µF/100V, C3,C4=470pF/2kV, WE 74466240007 700µH

RP15-AW

Vin = 9~36VDC, C1=6.8µF/50V, C2=6.8µF/50V, C3,C4=470pF/2kV, WE 7448227005 450µH
Vin = 18~75VDC, C1=2.2µF/100V, C2=2.2µF/100V, C3,C4=470pF/2kV, WE 7448229004 350µH

RP15-OVin = 12VDC nom., C1=10µF/25V, C2=10µF/25V, L1 = 10µH, WE 744822100002 175µH
Vin = 24VDC nom., C1=6.8µF/50V, C2=6.8µF/50V, L1 = 10µH, WE 744822100002 175µH
Vin = 48VDC nom., C1=2.2µF/100V, C2=2.2µF/100V, L1 = 18µH, WE 744822100002 175µH

RP15-OW

Vin = 9~36VDC, C1, C2, C3 =6.8µF/50V, WE 744822100002 175µH
Vin = 18~75VDC, C1=2 x 2.2µF/100V in parallel, C2,C3 =2.2µF/100V, L1 = 33µH, WE 7448229004 350µH

RP15-FVin = 12VDC nom., C1=4.7µF/50V, C2=Not Required, C3,C4=1nF/2kV, WE 7448229004 350µH
Vin = 24VDC nom., C1=3.3µF/50V, C2=Not Required, C3,C4=1nF/2kV, WE 7448229004 350µH
Vin = 48VDC nom., C1=2.2µF/100V, C2=2.2µF/100V, C3,C4=1nF/2kV, WE 7448229004 350µH

RP15-FW

Vin = 9~36VDC, C1=2.2µF/50V, C2=Not Required, C3,C4=1nF/2kV, WE 7448227005 450µH
Vin = 18~75VDC, C1=2.2µF/100V, C2=2.2µF/100V, C3,C4=1nF/2kV, WE 7448229004 350µH

RP20-FVin = 12VDC nom., C1=4.7µF/50V, C2=Not Required, C3,C4=1nF/2kV, WE 7448227005 450µH
Vin = 24VDC nom., C1=4.7µF/50V, C2=Not Required, C3,C4=1nF/2kV, WE 7448227005 450µH
Vin = 48VDC nom., C1=2.2µF/100V, C2=2.2µF/100V, C3,C4=1nF/2kV, WE 7448227005 450µH

RP20-FW

Vin = 9~36VDC, C1=4.7µF/50V, C2=Not Required, C3,C4=1nF/2kV, WE 7448227005 450µH
Vin = 18~75VDC, C1=2.2µF/100V, C2=2.2µF/100V, C3,C4=1nF/2kV, WE 7448229004 350µH

RP30-EVin = 12VDC nom., C1=4.7µF/25V, C2=Not Required, C3,C4=1nF/2kV, WE 7448227005 450µH
Vin = 24VDC nom., C1=6.8µF/50V, C2=6.8µF/50V, C3,C4=1nF/2kV, WE 7448227005 450µH
Vin = 48VDC nom., C1=2.2µFII2.2µF/100V, C2=2.2µFII2.2µF/100V, C3,C4=1nF/2kV, WE 7448227005 450µH

RP30-EW

Vin = 9~36VDC, C1=6.8µF/50V, C2=6.8µF/50V, C3,C4=1nF/2kV, WE 7448227005 450µH
Vin = 18~75VDC, C1=2.2µF II 2.2µF/100V, C2=2.2µF II 2.2µF/100V, C3,C4=1nF/2kV, WE 7448227005 450µH
Continued on next page

A-32

2014

www.recom-international.com

Powerline DC-DC Application Notes
RP30-FVin = 12VDC nom., C1, C2, C3 =10µF/25V, C4, C5, C6=1nF/2kV, CMC1 = WE 744841330 30µH, CMC2 =WE 744842565 65µH
Vin = 24VDC nom., C1, C2, C3 =4.7µF/50V, C4, C5, C6=1nF/2kV, CMC1 = WE 744841330 30µH, CMC2 =WE 744842565 65µH
Vin = 48VDC nom., C1, C2, C3 =2.2µF/100V, C4, C5, C6=1nF/2kV, CMC1 = WE 744841330 30µH, CMC2 =WE 744842565 65µH

RP30-FW

Vin = 9~36VDC, C1, C2, C3 =4.7µF/50V, C4, C5, C6=1nF/2kV, CMC1 = WE 744841330 30µH, CMC2 =WE 744842565 65µH
Vin = 18~75VDC, C1, C2, C3 =4.7µF/50V, C4, C5, C6=1nF/2kV, CMC1 = WE 744841330 30µH, CMC2 =WE 744842565 65µH

RP40-G

Vin = 12VDC nom., C1=4.7µF/50V, C2=Not Required, C3,C4=1nF/2kV, WE 7448227005 450µH
Vin = 24VDC nom., C1=6.8µF/50V, C2=6.8µF/50V, C3,C4=1nF/2kV, WE 7448227005 450µH
Vin = 48VDC nom., C1=2.2µF II 2.2µF/100V, C2=2.2µF II 2.2µF/100V, C3,C4=1nF/2kV, WE 7448640395 820µH

RP40-GW

Vin = 9~36VDC, C1=4.7µF/50V, C2=4.7µF/50V, C3,C4=1nF/2kV, WE 7448227005 450µH
Vin = 18~75VDC, C1=2.2µF II 2.2µF/100V, C2=2.2µF II 2.2µF/100V, C3,C4=1nF/2kV, WE 7448640395 820µH

RP60-G

Vin = 24VDC nom., C1=4.7µF/50V, C2=4.7µF/50V, C3,C4=1nF/2kV, WE 7448227005 450µH
Vin = 48VDC nom., C1=2.2µF II 2.2µF/100V, C2=2.2µF II 2.2µF/100V, C3,C4=1nF/2kV,WE 7448640395 820µH

Recommended PCB Layouts

C3
C1

4

3

1

2

C2

100
nF

Standard EMC Filter

CMC
C4

470
pF

C1
RP15-O Open Frame
Converters

4

3

1

2

CMC

C2 C3

L1
470
pF

www.recom-international.com

2014

A-33

Powerline DC-DC Application Notes
Recommended PCB Layouts
C6
C5

RP30-S_DF
RP30-S_DFW
C1

4

3

1

2

CMC-1

C2

C3

4

3

1

2

CMC-2

C4

General Information about Recom Common Mode Chokes
Recom common mode chokes are all RoHS conform. Maximum Rated Voltage = 500VDC
Operating Temperature = -40°C ~ +105°C

A-34

2014

www.recom-international.com

Powerline DC-DC Application Notes
Definitions and Testing
General Test Set-Up
DC Power
Source

A

+V

A

DC/DC
Converter
under TestV

V ( VDC or VRMS )Adjustableload-V
Figure 1-3: General DC/DC converter test set-up

Note: If the converter is under test withremote sense pins, connect these pins

to their respective output pins. All tests
are made in ”Local sensing“ mode.

Input Voltage Range

The minimum and maximum input voltage limits within which a converter

will operate to specifications.

PI Filter

An input filter, consisting of two capacitors,
connected before and after a series
inductor to reduce input reflected ripple
current. The effective filter is C1/L
+ L/C2, so the inductor filter element isdoubly effective.

Output Voltage Accuracy

With nominal input voltage and rated
output load from the test set-up, the DC
output voltage is measured with anaccurate, calibrated DC voltmeter.
Output voltage accuracy is the difference
between the measured output voltage
and specified nominal value as apercentage. Output accuracy (as a %) isthen derived by the formula:

L
Input

C1

C2

OutputFigure 2: PI Filter

Vout – Vnom
Vnom N

X100

Vnom is the nominal output specified in
the converter data sheet.

Voltage Balance

For a multiple output power converter,
the percentage difference in the voltage

level of two outputs with opposite polarrities and equal nominal values.

Line Regulations

Make and record the following measurements with rated output load at +25°C:● Output voltage at nominal line
(input) voltage.
Vout N● Output voltage at high line (input)
voltage.
Vout H● Output voltage at low line (input)
voltage.
Vout LThe line regulation is Vout M (the maximum of the two deviations of output) for
the value at nominal input in percentage.

www.recom-international.com

2014

Vout M – Vout N
Vout N

X100

A-35

Powerline DC-DC Application Notes
Definitions and Testing
Make and record the following measurements with rated output load at +25°C:● Output voltage with rated load
connected to the output. (Vout FL)● Output voltage with no load or theminimum specified load for the
DC-DC converter. (Vout ML)

Load regulation is the difference between
the two measured output voltages as apercentage of output voltage at rated
load.

Efficiency

The ratio of output load power consumption
to input power consumption expressed
as a percentage. Normally measured atfull rated output power and nominal line
conditions.

Switching Frequency

The rate at which the DC voltage is switched in a DC-DC converter or switching
power supply. The ripple frequency isdouble the switching frequency in pushpull designs.

Output Ripple and Noise

Because of the high frequency content
of the ripple, special measurement techniques must be employed so that correct
measurements are obtained. A 20MHz
bandwidth oscilloscope is used, so thatall significant harmonics of the ripple
spike are included.
This noise pickup is eliminated as shownin Figure 3, by using a scope probe withan external connection ground or ringand pressing this directly against theoutput common terminal of the power
converter, while the tip contacts the voltage output terminal. This provides theshortest possible connection across theoutput terminals.

Load Regulation

Vout ML – Vout FL
Vout FL

X100

Figure 3:

A-36

2014

www.recom-international.com

Powerline DC-DC Application Notes
Definitions and Testing
Output Ripple and Noise (continued)

Transient Recovery Time

Figure 4 shows a complex ripple voltage
waveform that may be present on the
output of a switching power supply.
There are three components in the waveform, first is a charging component thatoriginates from the output rectifier andfilter, then there is the discharging component due to the load discharging theoutput capacitor between cycles, andfinally there are small high frequency
switching spikes imposed on the low
frequency ripple.

Peak-Peak
AmplitudeTime

Figure 4: Amplitude

The time required for the power supply
output voltage to return to within a specified percentage of rated value, following a step change in load current.

Transient
Recovery Time

OvershootOutputVoltage
5V + U
5V

Undershoot

5V - L

V out

U: upper limit
L: lower limit

Load

I out

Time

Figure: 5 Transient Recovery Time

Current Limiting

output current is limited to prevent
damage of the converter at overload
situations. If the output is shorted, theFold Back Current Limiting

A method of protecting a power supply
from damage in an overload condition,
reducing the output current as the load
approaches short circuit.

output voltage is regulated down so thecurrent from the outputs cannot be
excessive.

V out

Rated Io

I out

Figure 6: Fold Back Current LimitingTime

www.recom-international.com

2014

A-37

Powerline DC-DC Application Notes
Definitions and Testing
Isolation

The electrical separation between the
input and output of a converter, (consisting of resistive and capacitive isola-

Break-Down Voltage

The maximum continuous DC voltage,
which may be applied between the input
and output terminal of a power supply
without causing damage.
Typical break-down voltage for DC-DC
converters is 1600VDC because theequivalent DC isolation for 230VAC
continuous rated working voltage is1500VDC.

tion) normally determined by transformer characteristics and circuit spacing.

R

Resistive andCapacitive Isolation

C

Input

RectifierandRegulator

OutputBreakdown Voltage

Figure 7:

With the power converter in a temperature test chamber at full rated output
load, make the following measurements:● Output voltage at +25°C ambient
temperature.
● Set the chamber for maximum
operating ambient temperature
and allow the power converter tostabilize for 15 to 30 minutes.
Measure the output voltage.
● Set the chamber to minimum
operating ambient temperature andallow the power converter tostabilize for 15 to 30 minutes.

● Divide each percentage voltage

Ambient Temperature

The temperature of the still-air immediately surrouding an operating
power supply. Care should be taken
when comparing manufacturer’s da-tasheets that still-air ambient temperature and not case temperature isquoted.

Operating Temperature Range

The range of ambient or case temperature within a power supply at which

it operates safely and meets its
specifications.

Storage Temperature Range

The range of ambient temperatures
within a power supply at non-opera-ting condition, with no degradation inits subsequent operation.

Temperature Coefficient

A-38

2014

deviation from the +25°C ambient
value by the corresponding temperature change from +25°C
ambient.
The temperature coefficient is the higher
one of the two values calculated above,
expressed as percent per change centigrade.

www.recom-international.com

Powerline DC-DC Application Notes
Trim Tables
Some converters from our Powerline offer
the feature of trimming the output voltage ina certain range around the nominal value
by using external trim resistors.
Because different series use different circuits for trimming, no general equation canbe given for calculating the trim resistors.

Output Voltage Trimming:

The following trimtables give values forchosing these trimming resistors.
If voltages between the given trim points
are required, extrapolate between the twonearest given values to work out the resistor required or use a variable resistor to
set the voltage.

Single Output Voltage Trim Tables
RP15-, RP20-, RP30-, RP40-, RP60- xx3.3S(For RP15-SA/SAW and RP15-SO/SOW see next page)

Trim up
Vout =
RU =

1
3,333
57.93

2
3,366
26.16

3
3,399
15.58

4
3,432
10.28

5
3,465
7.11

6
3,498
4.99

7
3,531
3.48

8
3,564
2.34

9
3,597
1.46

10
3,63
0.75

%
Volts
KOhms

Trim down
Vout =
RD =

1
3,267
69.47

2
3,234
31.23

3
3,201
18.49

4
3,168
12.12

5
3,135
8.29

6
3,102
5.74

7
3,069
3.92

8
3,036
2.56

9
3,003
1.50

10
2,97
0.65

%
Volts
KOhms

RP15-, RP20-, RP30-, RP40-, RP60- xx05S(For RP15-SA/SAW and RP15-SO/SOW see next page)

Trim up
Vout =
RU =

1
5,05
36.57

2
5,1
16.58

3
5,15
9.92

4
5,2
6.58

5
5,25
4.59

6
5,3
3.25

7
5,35
2.30

8
5,4
1.59

9
5,45
1.03

10
5,5
0.59

%
Volts
KOhms

Trim down
Vout =
RD =

1
4,95
45.53

2
4,9
20.61

3
4,85
12.31

4
4,8
8.15

5
4,75
5.66

6
4,7
4.00

7
4,65
2.81

8
4,6
1.92

9
4,55
1.23

10
4,5
0.68

%
Volts
KOhms

RP15-, RP20-, RP30-, RP40- ,RP60-xx12S(For RP15-SA/SAW and RP15-SO/SOW see next page)

Trim up
Vout =
RU =

1
12,12
367.91

2
12,24
165.95

3
12,36
98.64

4
12,48
64.98

5
12,6
44.78

6
12,72
31.32

7
12,84
21.70

8
12,96
14.49

9
13,08
8.88

10
13,2
4.39

%
Volts
KOhms

Trim down
Vout =
RD =

1
11,88
460.992
11,76207.95

3
11,64
123.60

4
11,52
81.42

5
11,4
56.12

6
11,28
39.25

7
11,16
27.20

8
11,04
18.16

9
10,92
11.13

10
10,8
5.51

%
Volts
KOhms

RP15-, RP20-, RP30-, RP40-, RP60- xx15S(For RP15-SA/SAW and RP15-SO/SOW see next page)

Trim up
Vout =
RU =

1
15,15
404.182
15,3180.593
15,45106.06

4
15,6
68.80

5
15,75
46.44

6
15,9
31.53

7
16,05
20.88

8
16,2
12.90

9
16,35
6.69

10
16,5
1.72

%
Volts
KOhms

Trim down
Vout =
RD =

1
14,85
499.82

2
14,7223.41

3
14,55
131.27

4
14,4
85.20

5
14,25
57.56

6
14,1
39.14

7
13,95
25.97

8
13,8
16.10

9
13,65
8.42

10
13,5
2.282

%
Volts
KOhms

www.recom-international.com

2014

A-39

Powerline DC-DC Application Notes
Trim Tables
RP15-S_DA, RP15 S:DAW Output Voltage Trim Tables
RP15-xx3.3SA, RP15-xx3.3SAW, RP15-xx3.3SO, RP15-xx3.3SOW
Trim up
Vout =
RU =

1
3,333
385.072
3,366
191.51

3
3,399
126.99

4
3,432
94.73

5
3,465
75.37

6
3,498
62.47

7
3,531
53.25

8
3,564
46.34

9
3,597
40.96

10
3,63
36.66

%
Volts
KOhms

Trim down
Vout =
RD =

1
3,267
116.72

2
3,234
54.78

3
3,201
34.13

4
3,168
23.81

5
3,135
17.62

6
3,102
13.49

7
3,069
10.54

8
3,036
8.32

9
3,003
6.60

10
2,97
5.23

%
Volts
KOhms

RP15-xx05SA, RP15-xx05SAW, RP15-xx05SO, RP15-xx05SOW
Trim up
Vout =
RU =1
5,05
253.452
5,1
125.70

3
5,15
83.12

4
5,2
61.82

5
5,25
49.05

6
5,3
40.53

7
5,35
34.45

8
5,4
29.89

9
5,45
26.34

10
5,5
23.50

%
Volts
KOhms

Trim down
Vout =
RD =1
4,95
248.342
4,9120.59

3
4,85
78.01

4
4,8
56.71

5
4,75
43.94

6
4,7
35.42

7
4,65
29.34

8
4,6
24.78

9
4,55
21.23

10
4,5
18.39

%
Volts
KOhms

RP15-xx12SA, RP15-xx12SAW, RP15-xx12SO, RP15-xx12SOW
Trim up
Vout =
RU =

1
12,12
203.22

2
12,24
99.06

3
12,36
64.33

4
12,48
46.97

5
12,6
36.56

6
12,72
29.61

7
12,84
24.65

8
12,96
20.93

9
13,08
18.04

10
13,2
15.72

%
Volts
KOhms

Trim down
Vout =
RD =

1
11,88
776.562
11,76
380.72

3
11,64248.784
11,52
182.81

5
11,4
143.22

6
11,28
116.83

7
11,16
97.98

8
11,04
83.85

9
10,92
72.85

10
10,8
64.06

%
Volts
KOhms

RP15-xx15SA, RP15-xx15SAW, RP15-xx15SO, RP15-xx15SOW
Trim up
Vout =
RU =

1
15,15
161.56

2
15,3
78.22

3
15,45
50.45

4
15,6
36.56

5
15,75
28.22

6
15,9
22.67

7
16,05
18.70

8
16,2
15.72

9
16,35
13.41

10
16,5
11.56

%
Volts
KOhms

Trim down
Vout =
RD =

1
14,85
818.222
14,7401.56

3
14,55
262.674
14,4193.22

5
14,25
151.56

6
14,1
123.787
13,95103.94

8
13,8
89.06

9
13,65
77.48

10
13,5
68.22

%
Volts
KOhms

A-40

2014

www.recom-international.com

Powerline DC-DC Application Notes
Trim Tables
Dual Output Voltage Trim Tables
RP15-, RP20, RP30-, RP40- xx12D
Trim up
Vout =
RU =

1
24,24
218.21

2
24,48
98.10

3
24,72
58.07

4
24,96
38.05

5
25,2
26.04

6
25,44
18.03

7
25,68
12.32

8
25,92
8.03

9
26,16
4.69

10
26,4
2.02

%
Volts
KOhms

Trim down
Vout =
RD =

1
23,76
273.442
23,52
123.02

3
23,28
72.87

4
23,04
47.80

5
22,8
32.76

6
22,56
22.73

7
22,32
15.57

8
22,08
10.20

9
21,84
6.02

10
21,6
2.67

%
Volts
KOhms

RP15-, RP20-, RP30-, RP40- xx15D
Trim up
Vout =
RU =1
30,3
268.29230,6120.64

3
30,9
71.43

4
31,2
46.82

5
31,5
32.06

6
31,8
22.21

7
32,1
15.1

8
32,4
9.91

9
32,7
5.81

10
33
2.53

%
Volts
KOhms

Trim down
Vout =
RD =1
29,7
337.71

2
29,4
152.02

3
29,1
90.13

4
28,8
59.18

5
28,5
40.61

6
28,2
28.23

7
27,9
19.39

8
27,6
12.76

9
27,3
7.60

10
27
3.47

%
Volts
KOhms

www.recom-international.com

2014

A-41

Powerline DC-DC Application Notes
Undervoltage Lockout
Undervoltage Lockout

At low input voltages, the input currents
can exceed the rating of the converter.
Therefore, converters featuring under-

voltage lockout will automitically shut
down if the input voltage is too low. As
the input voltage rises, they will restart.

Undervoltage Lockout Tables

Converter Series

Nominal Input Voltage

Switch ON
input voltage

Switch OFF
input voltage

RP08-S_DAW

24V (9~36VDC)
48V (18~75VDC)

9VDC
18VDC

8VDC
16VDC

RP12-S_DA

12V (9~18VDC)
24V (18~36VDC)
48V (36~75VDC)

9VDC
18VDC
36VDC

8VDC
16VDC
33VDC

RP12-S_DAW

24V (9~36VDC)
48V (18~75VDC)

9VDC
18VDC

8VDC
16VDC

RP15-S_DA, RP15-S_DO

12V (9~18VDC)
24V (18~36VDC)
48V (36~75VDC)

9VDC
17VDC
33VDC

8VDC
14.5VDC
30.5VDC

RP15-S_DAW, RP15-S_DOW

24V (9~36VDC)
48V (18~75VDC)

9VDC
18VDC

8VDC
16VDC

RP15-S_DFW

24V (9~36VDC)
48V (18~75VDC)

9VDC
18VDC

7.5VDC
15VDC

RP20-S_DFW

24V (9~36VDC)
48V (18~75VDC)

9VDC
18VDC

7.5VDC
15VDC

RP30-S_DE

12V (9~18VDC)
24V (18~36VDC)
48V (36~75VDC)

9VDC
17.8VDC
36VDC

8VDC
16VDC
33VDC

RP30-S_DEW

24V (10~40VDC)
48V (18~75VDC)

10VDC
18VDC

8VDC
16VDC

RP40-S_D_TG

12V (9~18VDC)
24V (18~36VDC)
48V (36~75VDC)

9VDC
17.8VDC
36VDC

8VDC
16VDC
34VDC

RP30-S_DGW

24V (9~36VDC)
48V (18~75VDC)

9VDC
18VDC

8VDC
16VDC

RP60-SG24V (18~36VDC)
48V (36~75VDC)

17VDC
34VDC

15VDC
32VDC

A-42

2014

www.recom-international.com

DC-DC Converter Applications
Thermal ManagementThe Laws of Thermodynamics

Thermal ManagementThermal Impedance

Smaller, more powerful, better performance…are the buzzwords in the area of DC/DC
module power supplies. Good thermal
management of the heat generated has
become an important part of the designprocess. But what needs to be done?

The Thermal Impedance is a measure of how
effectively heat can flow from inside the converter to its surroundings. It is measured in°C/Watt. It is possible to further lower thethermal resistance to ambient by fitting an
external heat sink as this increases the surface
area from which heat can be transferred to thesurrounding air. The thermal impedance canalso be lowered by blowing air across theconverter as moving air can transfer more heataway from the converter as stationary air.

An indisputable fact is that the efficiency of any
energy conversion process is always less than
100%. This means that a part of the energy
being converted goes astray as heat and that
ultimately this waste heat must be removed.
The laws of thermodynamics state that heat
energy can only flow from a warmer to acolder environment. So, for DC/DC converters,
this means that if the internal heat is to bedissipated out of the module, that the ambient
temperature must always be lower than the
maximum allowable internal temperature. The
larger this difference, the more effectively
waste heat can flow out of the converter.
But which temperature specifications in thedatasheets are to be consulted for the thermal
calculations? RECOM declares two values in
its datasheets, Operating Temperature Range(with or without derating) and the Maximum
Case Temperature. Some manufacturers evenclaim that these two values are the same.
The case (surface) temperature of DC/DC
modules are typically given as around +100°C.
This value appears at first to be very high;however this figure includes not only the selfwarming through internal losses but also theambient temperature itself.
Remember: The smaller the difference
between case surface and ambient, so thesmaller the amount of heat that can be lost to
the surroundings. If a converter has highinternal dissipation, then it will be more
affected by a small temperature difference
than a converter with low internal dissipation.
The internal losses occur mainly throughswitching losses in the transistors, rectification
losses, core losses in the transformer andresistive losses in the windings and tracks. The
maximum allowable internal temperature isdetermined by either the curie temperature of
the transformer core material, the maximum
junction temperature of the switchingtransistors or rectification diodes or the
maximum operating temperature of thecapacitors: whichever is the lowest.

www.recom-international.com

Recom datasheets always show the thermal
impedance without a heatsink and withnatural convection (still air).
The datasheets also state the minimum andmaximum ambient operating temperature
rather than just the maximum casetemperature because this is easiest for the end
user to measure and to monitor. The advantage
is that true ambient temperature can be measured in the actual application and it need not
be calculated theoretically, plus the results arevalid for both sealed and vented constructions
with a through-flow of cooling air.
Nevertheless, the maximum case temperatureis useful to decide on a suitably dimensioned
heat sink so that the maximum casetemperature is not exceeded at the maximum
ambient temperature.
The internal losses and thermal resistances
can also be derived mathematically.
For the calculations, Ohm’s Law of R=V/I canbe modified so that R becomes thermal resistance, V becomes temperature and I becomespower dissipation. The following equations canthus be derived:

where
R THcase-ambient = Thermal impedance(from the case to the ambient surroundings)
T case =Case temperature
T ambient=Environment temperature
P dissipation =Internal losses
P in =Input power
P out =Output powerη(oper) =efficiency under the given operating
conditions
2014

With help of the above formulae, the maximum
allowable ambient temperature for a given setof operating conditions can be calculated - but
it is important to remember that efficiency isdependent on both the output load and the
input voltage.
The formulae also demonstrate that casetemperature is not the same as operating
temperature, as is so often falsely claimed.
A practical example:
Take the RP30-4805SE with 80% load:
What is the maximum operating temp?
From the datasheet text and graphs, thefollowing information can be found:
R THcase-ambient = 10°C/W
T case = 100°C maximum
T ambient=unknown
P dissipation must be calculated from:
P out = 30 x 80% = 24W
η(oper) = 90% (from Eff vs Load Graph)
P diss. = 24/0.9 -24 = 2.66 Watts.
Thus
10W/°C = (100 - T amb) / 2.66W
and T amb max. = 73.4°C
At 100% load, this figure reduces to 64.4°C
At 100% load and over the full input voltage
range, this figure reduces further to 59.1°C
If the thermal dissipation calculations revealthat the DC/DC Module will overheat at thedesired ambient operating temperature, thenthere are still a number of options available toreach a solution.
One option is to derate the converter, i.e, use ahigher power converter running at less than fullload. The derating diagrams in the datasheets
essentially define the maximum load at any
given temperature within the operating
temperature range. The derating curves are in
reality not so linear as they are declared inmost datasheets. However, reliable
manufacturers will always err on the safe side
so that the values given can be safely relied onin practice.
If the converter has a plastic case, then thenext largest case size with the same power
rating could be chosen to increase theavailable surface area. However, care must be
taken not to compromise on efficiency
otherwise no net gain will be made.

A-43

DC-DC Converter Applications

If the converter has a metal case, then addinga heat sink is can be very effective, particularly
in conjunction with a forced-air cooling system.
If a heat sink is used with fan cooling, then thethermal resistance equation becomes:
RTHcase-ambient = RTHcase-heatsink + RTHheatsink-ambient
where
RTHcase-ambient =Thermal impedance(from the case to the ambient surroundings)
RTHcase-heatsink =Thermal impedance(from the case to the heat sink)
RTHheatsink-ambient =Thermal impedance(from the heat sink to ambient)
The value of RTH heatsink-ambient includes
the thermal resistance of the heat sink as wellas the thermal resistance of any thermallyconductive paste or silicon pads used for abetter thermal contact to the case. If these heattransfer aids are not applied, then a value ofapproximately 0.2 K/W must be added to thethermal resistance of the heat sink alone.
When establishing of the value of RTH
heatsink-ambient it is also necessary to know
how much air is being blown across the heatsink fins. These values are most often given inlfm (linear feet per minute) and declared by the
fan manufacturer. The conversion to m/s is
100lfm = 0.5 m/s.

Heatsink mounted on casewithout thermal conductivity paste

RTH case-heatsink = ca. 1…2 °C/W

Heatsink mounted on casewith thermal conductivity paste

RTH case-heatsink = ca. 0,5…1 °C/W

Heatsink mounted on casewith thermal conductivity pasteand electrical isolation film

RTH case-heatsink = ca. 1…1,5 °C/W

Therefore, If a heatsink is mounted on theconverter, it’s thermal resistance has to be atleast:
RTHcase-ambient = RTHcase-heatsink + RTHheatsink-ambient =6.1°C/W - 1°C/W = 5.1°C/W

If however, the results of your calculations ormeasurements are border-line, then the issue
must be examined in more depth. So, forexample, there is a difference in thermal
performance between vertically andhorizontally mounted modules, between static
air and freely convecting air and with air at low
atmospheric pressures.

1.0
NATURAL CONVECTION
EFFECTIVENESS

Thermal ManagementHeat Sinking

0.8
0.6
0.4
0.2
0.0

0

2000

4000

8000

20000

40000

80000

ALTITUDE (FT)Calculation of heatsinks size:
Example: RP30-2405SEW starts derating
without heatsink at +65°C but the desired
operation is 30W at +75°C so the size ofthe heatsink has to be calculated.
Pout = 30W
Efficiency = 88% max.

Pd =Pout - Pout = 30W - 30W = 4.1W
Efficiency
88%

Tcase = 100°C (max. allowed case temperature)Tambient = 75°C
RTHcase-ambient = Tcase-Tambient = 100°C-75°C
PD
4.1W=6.1°C/W

So it has to be ensured that the thermal
resistance between case and ambient is
6,1°C/W max.
When mounting a heatsink on a case there isa thermal resistance RTH case-heatsink between
case and heatsink which can be reduced byusing thermal conductivity paste but cannot be
eliminated totally.
A-44

2014

www.recom-international.com

Powerline DC-DC Application Notes
Heat Sinks available from Recom
7G-0047C (12°C/W)- includes double-sided adhesive pad and clips

7G-0020C (9.5°C/W) - includes double-sided adhesive pad and clips
A : A ( 5 : 1mm)
3.2 ±0.1

49.80 ±0.2

1.30
R 0.6524.20±0.2

12.00 ±0.2
A :A
R2

1.30
1.40

1.2 ±0.1

1.30
1.40
2.00

12.00 ±0.25.60 ±0.11.70 ±0.1

www.recom-international.com

2014

A-45

Powerline DC-DC Application Notes
Heat Sinks available from Recom
7G-0011C (8.24°C/W)- includes double-sided adhesive pad and clips
A : A ( 5 : 1mm)

50.00 ±0.2
R 0.6537.40±0.2

15.00 ±0.2
1.30

A :A

1.40
1.30

3.00 ±0.1
1.00
2.00

27.00 ±0.25.60 ±0.11.70 ±0.1

7G-0026C (7.8°C/W)- includes double-sided adhesive pad and clips
3.2 ±0.1

49.80 ±0.2

A : A ( 5 : 1mm)
1.30

49.80 ±0.2

12.00 ±0.2
1.30
1.40

A :A

1.30
1.2 ±0.1

12.00 ±0.2

1.40
1.30

R 0.655.60 ±0.11.70 ±0.1

A-46

2014

www.recom-international.com

AC/DC Application Notes
Input Fuse

+Vout

L

Live
Time Delay
Fuse
NeutralAC/DC
ConverterN- VoutL+VoutTime Delay
Fuses

AC
INPUT

AC/DC
Converter

Adjustableload

Adjustableload- VoutN

Note: An input fuse is recommended forsafety and protection.
A time-delay or slo-blo fuse should be
fitted.
If the AC connector is not-polarised, thenfuses can be fitted to both inputs

Recommended Fuse Ratings<40W 1.5Amp
40W
2 Amp
60W
3 Amp

Earthing
+Vout

L

Live
Time Delay
Fuse

Neutral
Earth

AC/DC

N Converter

Adjustableload- VoutFG

Optional Link

Note: If the converter has a ground pin(FG), then it must be earthed to a safety
ground point.

Use thicker,shorter cables to ensure agood connection as this will also reducethe EMC interference.
-Vout can be also connected to FG to reference the output to Ground.

External Filter
LLive
NeutralTime Delay
Fuse

Line
FilterEarth

www.recom-international.com

AC/DC

N Converter
FG

Note: The RECOM RAC series contain a
built-in line filter to meet EN 55022 Class
B Conducted Emissions.

2014

+Vout
Adjustableload- VoutIf additional filtering is required, then an
external line filter module can be fitted.
The cabling between the external filter
and the converter should be kept as
short as possible and a central star-earth
wiring should be used.

A-47

AC/DC Application Notes
Combining ConvertersLDC-in ParallelAC
DC

Note: AC/DC converters can beparalleled to increase the output voltage
or to make a hot-swap circuit.
The inputs of two AC/DC converters cannot be wired in series to increase theinput voltage range.
However, single phase AC/DC converters
can be used with three phase supplies if
the input is connected via diodes.

AC

N

L

DC
AC
DC
AC

N

+Vo
0V
+Vo

2Vo

0V

+Vo
0V
+Vo

Vo

0V

Combining Converters-in Series

NeutralNote: A DC/DC converter or switchingregulator can be powered from theoutput of an AC/DC converter to add an
auxilliary output or negative rail.

+Vout

L

Live
Time Delay
Fuse

Earth

Live
NeutralTime Delay
Fuse

Earth

AC/DC
N Converter

R-78xx

FG

0V

L

+Vout

AC/DC
N Converter
FG

Aux.
load

DC

Main
load

+Vo

Main
load

DC

0V

-Vout

DC Inputs
Note: All AC/DC converters will also workwith DC inputs.
Check the individual datasheets for the
DC input voltage ranges.

L
200VDCTime Delay
Fuse

AC/DC
Converter
N

A-48

2014

+Vout
Adjustableload- Voutwww.recom-international.com

POWERLINE PLUS - CONTENTS
The POWERLINE PLUS uses ICE Technology. A combination of techniques
to minimise internal heat dissipation and maximise the heat transfer toambient to create a new converter series which offers high end performanceat a price which is significantly lower than conventional specialist converters.
RECOM - Green high-efficiency power solutions. SAVE ENERGY. NOW.

Introduction
The RPP series 2:1 and 4:1 input range DC/DC converters are ideal for high end industrial applications and COTS (Commercial Off-The-Shelf) Military applications, where a high ambient operating temperature converter is required.
The RPR series are specifically tailored to the requirements of Railway applications. These converters work under extreme operating conditions and are designed for input voltages up to 160VDC.
Both converters series feature ICE Technology, a revolutionary method of extending the temperature range without increasing
the converter dimensions over standard converters. The built-in aluminium heat sink ensures optimum heat transfer to ambient.
Although the case size is compact, the RPP series contain a built-in EN55022 Class B / FCC Level B filter and the RPR series
contains a built-in EN50121-3-2 Class A filter without the need for any external components.
All converters are fully protected with undervoltage lockout protection, overload, overcurrent and overvoltage protection, short circuit current limiting and overtemperature shutdown.
In addition, the converters have a quiescent current that is an order of magnitude lower than equivalent power converters.

DC/DC Converters with ICE Technology
SeriesPower[W]

Isolation[kVDC]

RPP20

20

9-18, 18-36, 36-75

RPP20 (W)20

9-36, 18-75

RPR20

20

12-36, 25-75, 40-160

RPP30

30

9-18, 18-36, 36-75

RPP30 (W)30

10-40, 18-75

RPR30

30

RPP40

40

10-40, 18-75

RPP40 (W)40

10-40, 18-75

RPR40

40

12-36, 25-75, 40-160

RPP50

50

18-36, 36-75

3.3, 5, 12, 15, 24

SingleRPR50

50

12-36, 25-75, 40-160

3.3, 5, (+/-)12, (+/-)15, (+/-)24

Single & Dual

2

Input Voltages[VDC]

Output Voltages
[VDC]

3.3
5
(+/-)12(+/-)15(+/-) 24

12-36, 25-75, 40-160

Case Options

RibbedFlat
Baseplate

Outputs

SingleDual

RPR-Series for Railway Applications
A-49

2014

www.recom-electronic.com

POWERLINE+ Application Notes
DC/DC-Converter

ICE
Technology

ICE Technology

I.C.E Technology
ICE (Innovation in Converter Excellence)
Technology uses a combination of techniques
to minimise internal heat dissipation andmaximise the heat transfer to ambient tocreate a new converter series which offers highend performance at a price which is significantly lower than conventional specialist converters.
The exact details of this technology mustremain secret, but the following brief resume
describes the main features of thistechnological breakthrough:Minimising internal heat dissipation
The difference between the input power andthe output power is the internal power
dissipation which generates heat within theconverter.
If the converter is inefficient at converting
power, then adding external heat sinks, baseplates or fans are remedies that cure thesymptoms rather than address the illness.
First and foremost, the converter must have thehighest possible efficiency over the entire input
voltage range and load conditions. Most power
converters are designed to be most efficient at
25°C, full load and nominal input voltage andthus offer a compromise performance whenlightly loaded or operated at the maximum
ambient temperature.
ICE Technology uses state-of-the-art
techniques to improve power convertion
efficiency by approximately 2% compared tostandard converters. A two per cent improvement may not sound much, but the difference
between a converter with 88% efficiency and
one with 90% efficiency is a 17% reduction in
the dissipated power. In addition, when lightly
loaded, the converters enter a power saving
mode and draw only a few milliamps from the
supply.

Maximising heat transfer
The rate of heat transfer between a hot bodyand its cooler surroundings is given by
Fourier’s Law: q=-k.ΔT
where q = rate of heat transfer
k = thermal conductivity
and ΔT = temperature difference
If k can be made larger, then the rate of heattransfer can still match or exceed the rate ofheat generation at lower temperature
differences ΔT and the converter will have an
extended operating temperature range.

www.recom-international.com

Techniques to improve thermal
conductivity
ICE Technology splits the thermal conductivity
problem into two areas and attacks each areaseperately using different techniques.

Electromagnetic Compatibility

Firstly, the internal heat transfer to the case ismaximised by a combination of novel
converter construction and clever thermal
design.

Although high temperature performance is asignificant feature of ICE Technology design, it
does not end there.

ICE converters use a construction where thehottest components (the switching FET, thetransformer and the synchronous rectification
FETs) are placed closest to the case wall. Thismethod of construction makes the
manufacture of the converter more difficult, but
this lack of compromise reduces greatly theinternal thermal impedance.

ICE Technology also addresses the need forelectromagnetic compatibility by incorporatinga built-in EN55022 Class B grade filter inside
the converter. The converter has been designed from the ground up to meet EMC requirements rather than a conventional design
process where first the converter is optimised
for performance and then an external filter isadded to combat the conducted interference.

Secondly, the rate of transfer of heat to thesurroundings is improved by a novel caseconstruction which incorporates a built-in heatsink. The case is also made from thick aircraft
grade aluminium rather than thin nickel-plated
copper to provide a better thermal junction
between the case and the high thermal
conductivity silicone potting material used
inside the converter.

By including the filter on the main PCB of theconverter, the track path lengths and
impedances between the filter and the noisegenerating components are reduced to theminimum and consequently smaller value
filter components can be used that fit into thecompact case dimensions of the Powerline+
converters without compromising on filter
performance.

Maximising highperformance

Safety and Protection

temperature

The final technique used in the construction of
ICE Technology converters is to use hightemperature internal components. The
maximum operating temperature of aconverter is dependent on the lowest
maximum permissible operating temperatureof any the components used. If the capacitors
are rated up to +85°C and the FETs are rated
at +160°C, then the limiting factor is the capacitor temperature of +85°C.
The temperature of the ferrite core used in thetransformer is also an important limiting
factor. If the transformer core temperature
exceeds the Curie temperature of the ferrite,then the transformer rapidly loses
performance.
ICE Technology converter uses hightemperature grade components to permit acase temperature of +120°C maximum. This
allows operation at up to +85°C ambient
without the need for fans to blow air over theconverter.
2014

ICE Technology converters are fully protectedfrom output short circuits, overload, output
over-voltage and over-temperature. In addition,
they feature under-voltage lockout that willautomatically disable the converter if the input
voltage falls below the minimum level.
The output is current limited which means that
temporary overloads can occur without theconverter shutting down. When overloaded, theoutput voltage will decrease to keep the
maximum power constant. For the 40W and
50W converters, if the overload is too high, theconverter will go into hiccup short circuit
protection mode. In this mode, the converter
will attempt to reconnect power every 10-20
milliseconds.
Output overvoltage protection is monitored bya separate and independent feedback circuit
and an internal thermistor sensor is used toprotect the converter against overheating.

A-50

POWERLINE+ Application Notes

Trim Tables

DC/DC-Converter
Powerline Plus Output Trim Tables

Single output Powerline Plus converters
offer the feature of trimming the output
voltage over a certain range around thenominal value by using external trim
resistors.
No general equation can be given for
calculating the trim resistors, but the

Output Voltage Trimming:

following trimtables give typical values forchosing these trimming resistors.
If voltages between the given trim points
are required, extrapolate between the twonearest given values to work out theresistor required or use a variable resistor
to set the output voltage.

RPP/RPRxx-xx3.3S (all types)
Trim up
Vout =
RU =

1
3,333
72.8

2
3,366
34.4

3
3,399
21.2

4
3,432
14.4

5
3,465
9.9

6
3,498
7.2

7
3,531
5.3

8
3,564
3.88

9
3,597
2.74

10
3,63
1.84

%
Volts
KOhms

Trim down
Vout =
RD =

1
3,267
101.3

2
3,234
36.2

3
3,201
21.0

4
3,168
13.65

5
3,135
9.2

6
3,102
6.0

7
3,069
4.12

8
3,036
2.56

9
3,003
1.34

10
2,97
0.87

%
Volts
KOhms

RPP/RPRxx-xx05S (all types)
Trim up
Vout =
RU =

1
5,05
109.7

2
5,1
51

3
5,15
31.2

4
5,2
20.3

5
5,25
14.2

6
5,3
9.87

7
5,35
7.1

8
5,4
5.0

9
5,45
3.38

10
5,5
2.08

%
Volts
KOhms

Trim down
Vout =
RD =

1
4,95
127.6

2
4,9
55.8

3
4,85
33.0

4
4,8
20.2

5
4,75
14.2

6
4,7
9.46

7
4,65
5.97

8
4,6
3.6

9
4,55
1.77

10
4,5
0.28

%
Volts
KOhms

RPP/RPRxx-xx12S (all types)
Trim up
Vout =
RU =

1
12,12
270

2
12,24
120

3
12,36
70

4
12,48
45.2

5
12,6
30.1

6
12,72
19.8

7
12,84
12.8

8
12,96
7.52

9
13,08
3.31

10
13,2
0

%
Volts
KOhms

Trim down
Vout =
RD =

1
11,88
270

2
11,76
120

3
11,64
70

4
11,52
45.2

5
11,4
30.1

6
11,28
19.8

7
11,16
12.8

8
11,04
7.52

9
10,92
3.31

10
10,8
0

%
Volts
KOhms

RPP/RPRxx-xx15S (all types)
Trim up
Vout =
RU =

1
15,15
337

2
15,3
150

3
15,45
87

4
15,6
56.2

5
15,75
37.5

6
15,9
24.7

7
16,05
16

8
16,2
9.4

9
16,35
4.16

10
16,5
0

%
Volts
KOhms

Trim down
Vout =
RD =

1
14,85
337

2
14,7
150

3
14,55
87

4
14,4
56.2

5
14,25
37.5

6
14,1
24.7

7
13,95
16

8
13,8
9.4

9
13,65
4.16

10
13,5
0

%
Volts
KOhms

A-51

2014

www.recom-electronic.com

BlockDiagrams

POWERLINE+ Application Notes
DC/DC-Converter
Powerline Plus Output Trim Tables
RPP/RPRxx-xx24S (all types)
Trim up
Vout =
RU =

1
24,24
270

2
24,48
120

3
24,72
70

4
24,96
45.2

5
25,20
30.1

6
25,44
19.8

7
24,68
12.8

8
25,92
7.52

9
26,16
3.31

10
26,4
0

%
Volts
KOhms

Trim down
Vout =
RD =

1
23,76
270

2
23,52
120

3
23,28
70

4
23,04
45.2

5
22,80
30.1

6
22,56
19.8

7
22,32
12.8

8
22,08
7.52

9
21,84
3.31

10
21,6
0

%
Volts
KOhms

Block Diagrams

Single Output - 3.3V and 5V Outputs
+Vin

+Vout
SwitchControlCom-Vin

ON/OFF
Control

Overtemp.
SensorPWM
Controller

Isolation

Overvoltage
SensorIsolation

Reference& Error AMP

Trim

Single Output - 12V, 15V and 24V Outputs
+Vin

+Vout

Com

-Vin

ON/OFF
Control

Overtemp.
Sensorwww.recom-international.com

PWM
Controller

Isolation

Overvoltage
SensorIsolation

Reference& Error AMP

2014

Trim

A-52

BlockDiagrams

POWERLINE+ Application Notes
DC/DC-Converter
Block Diagrams

Dual Output
+Vout

Com

+Vin

-Vout

-Vin

ON/OFF
Control

A-53

Overtemp.
SensorPWM
Controller

Isolation

Overvoltage
SensorIsolation

Reference& Error AMP

2014

www.recom-electronic.com

Application Notes
DC/DC Block Diagrams
Unregulated Single Output
RM, RL , RNM, RN, RO, RE, ROM,
R1S, RB-xxxxS, RA-xxxxS, RBMxxxxS, RK, RP-xxxxS, RxxPxxS,
RxxP2xxS, R2S, RI, REZ, RKZxxxxS, RV-xxxxS, RGZ, R0.25S

+Vin

+Vout
Oscillator
-Vout

-Vin
Unregulated Dual Output
RQD, R1D, RB-xxxxD, RA-xxxxD,
RBM-xxxxD, RH, RP-xxxxD,
RxxPxxD, RxxP2xxD, R2D, RCxxxxD, RD-xxxxD, RKZ-xxxxD, RVxxxxD, RJZ, R0.25S

+Vin

+Vout
Oscillator

Com
-Vout

-Vin
Unregulated Dual Isolated Output
RU, RUZ, R1DA

+Vin

+Vout1-Vout1

Oscillator+Vout2-Vout2-Vin
Post-Regulated Single Output
R1Z, R0.5Z, RY-xxxxS, RY-xxxxSCP, REC3-xxxxSR/H1

+Vin

Reg

+Vout

Oscillator
-Vout

-Vin
Post-Regulated Dual Output
RY-xxxxD, REC3-xxxxDR/H1

+Vin

Reg
Oscillator

Com
Reg

-Vin
A-54

+Vout

2014

-Vout
www.recom-international.com

Application Notes
DC/DC Block Diagrams
Regulated Single Output
RSO, RS, RS3, RW-xxxxS, REC3-xxxxSRW(Z)/H*, REC5-xxxxSRW(Z)/H*, REC7.5-xxxxSRW/AM/H*, REC08-xxxxSRW, REC10-xxxxSRW, REC15-xxxxSRW,
RP08-xxxxSA, RP08-xxxxSAW, RP10-xxxxSE, RP10-xxxxSEW, RP12-xxxxSA, RP12-xxxxSAW, RP15-xxxxSO, RP15-xxxxSOW, RP15-xxxxSA, RP15-xxxxSAW,
RP15-xxxxSF, RP15-xxxxSFW, RP20-xxxxSA, RP20-xxxxSAW, RP20-xxxxSF, RP20-xxxxSFW

+Vin

Noise
Filter

+Vout

-Vout
-Vin
Oscillator &Controller

Isolation

Reference& Error AMP

Regulated Dual Output
RSO-xxxxD, RS-xxxxD, RW-xxxxD, REC3-xxxxDRW(Z)/H*, REC5-xxxxDRW(Z)/H*, REC7.5-xxxxDRW/AM/H*, REC08-xxxxDRW, REC10-xxxxDRW, REC15xxxxDRW, RP08-xxxxDA, RP08-xxxxDAW, RP10-xxxxDE, RP10-xxxxDEW, RP12-xxxxDA, RP12-xxxxDAW, RP15-xxxxDF, RP15-xxxxDFW, RP15-xxxxDA, RP15xxxxDAW, RP20-xxxxDA, RP20-xxxxDAW, RP20-xxxxDF, RP20-xxxxDFW, RP30-xxxxDE, RP30-xxxxDEW, RP40-xxxxDG, RP40-xxxxDGW

+Vin

Noise
Filter

+Vout
Com
-Vout

-Vin
Oscillator &Controller

www.recom-international.com

Isolation

2014

Reference& Error AMP

A-55

Application Notes
DC/DC Block Diagrams
Regulated Triple Output
RP40-05xxTG

+Vaux
Com
+Vin

Noise
Filter-Vaux+Vout1-Vout1-Vin
Oscillator &Controller

Isolation

Reference& Error AMP

Regulated Single Output, Synchronous Rectification
RP20-xxxxSF, RP20-xxxxSA, RP20-xxxxSAW, RP30-xxxxSE, RP30-xxxxSEW, RP40-xxxxSG, RP40-xxxxSGW, RP60-xxxxSG

+Vin

+Vout
SwitchControl

Com

-Vin
PWM
Controller

Isolation

Reference& Error AMP

Trim

ON/OFF
Control

A-56

2014

www.recom-international.com

Application Notes
AC/DC Block Diagrams
RAC05-xxSA, RAC10-xxSA, RAC15-xxSA, RAC20-xxSA, RAC30-xxSA, RAC60-xxSB

+Vout
L

Line Filter

N

Rectifier

-Vout

FG

PWM
Controller

Isolation

Reference& Error AMP

RAC01-xxSC, RAC02-xxSC, RAC03-xxSC, RAC03-xxSA, RAC04-xxSA, RAC05-xxSB, RAC06-xxSC, RAC10-xxSB, RAC15-xxSB, RAC30-xxSA,RAC40-xxSA, RAC40-xxSB

L

+Vout
Rectifier

-Vout

N
PWM
Controller

www.recom-international.com

Isolation

2014

Reference& Error AMP

A-57

Application Notes
AC/DC Block Diagrams
RAC05-xxDA, RAC10-xxDA, RAC15-xxDA, RAC20-xxDA, RAC30-xxDA

L

+Vout
FilterRectifier

Com

-Vout

N

FG
Overcurrent
Protection

PWM
Controller

Isolation

Reference& Error AMP

RAC06-xxDC, RAC15-xxDB, RAC30-xxDA, RAC40-xxDA, RAC40-xxDB

L

+Vout
FilterRectifier

-Vout

N

Overcurrent
Protection

A-58

PWM
Controller

Isolation

2014

Reference& Error AMP

www.recom-international.com

Application Notes
AC/DC Block Diagrams
RAC15-05xxTA, RAC20-05xxTA+5Vout+5V Rtn+Vout
LLine Filter

N

Com

Rectifier

-Vout

FG

Overcurrent
Protection

PWM
Controller

Isolation

Reference& Error AMP

RAC15-05xxTB, RAC30-05xxTA, RAC40-05xxTA+5Vout+5V Rtn+Vout

LLine Filter

Com

Rectifier

-Vout

N

Overcurrent
Protectionwww.recom-international.com

PWM
Controller

Isolation

2014

Reference& Error AMP

A-59

Transport Tubes
No.

Types

1.

RO, RM, RN, RNM, RE, ROM, RB, RBM, RK, RH, RP, RU, RI, RD, RKZ, RUZ, RY,
R-78xx-0.5, R-78xx-1.0, R-78Cxx-1.0
RS, RSO, RS3
RJZ, RGZ, RW2(B)RSS, RSD, RZ, R1S, R1D, R1Z, R0.5Z
RTD, RTS, RSZ, R-78Axx-xx SMD, R2S, R2D, R-78AAxx-xx SMD
RV, RW-S, RxxPxx, RxxP2xx, RW2(A)-SMD
R-5xxxPA, R-6xxxP, R-7xxxP, RW-D,
REC3-, REC3.5, REC5-, REC6-, REC7.5RP08, RP12, REC8, REC10, RCD-24-xxx
RP15-O, RP15-OW, RP15-A, RP15-AW, REC15
RAC01, RAC02
RP10, RP15, RP20, RP30, RP40
RP08-SMD, REC3-SMD, REC5-SMD, REC7.5-SMD
R-78Bxx-xx, R-78HBxx-xx
R-78Bxx-xxL, R-78HBxx-xxL
R-5xxxDA, R-6xxxD, R-7xxxD

2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.

1.

2.

TUBE LENGTH = 520±2.0

A-60

3.

TUBE LENGTH = 520±1.5

2014

TUBE LENGTH = 520±1.0

www.recom-international.com

Transport Tubes
4.

5.

TUBE LENGTH = 530±2.0

6.

TUBE LENGTH = 530±2.0

7.

TUBE LENGTH =530±2.0

8.

TUBE LENGTH = 530±2.0

TUBE LENGTH = 530±2.0

10.

9.

36.8±0.5

18.5±0.527.4±0.5
21.7±0.5

TUBE LENGTH = 530±2.0

www.recom-international.com

TUBE LENGTH = 520±1.0

2014

A-61

Transport Tubes
11.
54.0 ± 0.5
50.0 ± 0.5

22.0 ± 0.5
20.0 ± 0.5
7.0 ± 0.5
1.2 ± 0.2

6.0 ± 0.5
10.0 ± 0.5
15.0 ± 0.5

12.

TUBE LENGTH = 254mm ± 2.0

13.
9.3 ± 0.25

0.63 ± 0.15

23.8 ± 0.25

18.5 ± 0.25

4.3 ± 0.25

TUBE LENGTH = 520mm ± 2.0

15.

14.
6.5±0.25
0.7±0.2

17.15±0.25

17.8±0.25
7.62± 0.25

9.2±0.25

0.5± 0.127

5±0.2511.1±0.25
10.2±0.25

3.3±0.25

18.42±0.25
11.68±0.25
12.32±0.25

TUBE LENGTH = 520mm ± 2.0

A-62

2.41±0.25

TUBE LENGTH = 520mm ± 2.0

2014

www.recom-international.com

Tape and Reel (Suffix -R)

RSS(8)-xxxx & R1S(8)-xxxx tape outline dimensions

13.2

Spocket hole Ø1.50+0.1/-0
Spocket hole tolerance over any 10 pitches ±0.2

0.40 ±0.05

16.00
2.00

4.00

11.4

1.75

7.6

11.5
24.0 ±0.2

RECOM
R1S-0505
xxxx

All dimensions in mm xx.xx ±0.1
1. 10 sprocket hole pitch cumulative tolerance ±0.20
2. All dimensions meet EIA-481-2 requirements
3. Component load per 13" reel : 500 pcs

RECOM
R1S-0505
xxxx

4. The diameter of disc center hole is 13.0mm

www.recom-international.com

RECOM
R1S-0505
xxxx

2014

A-63

Tape and Reel (Suffix -R)

RSD(10)-xxxx, RSS12-xxxx, RSD12-xxxx, R1D(10)-xxxx, R1S12-xxxx, R1D12-xxxx,& RZ-xxxx tape outline dimensions

17.75

Spocket hole Ø1.50+0.1/-0
Spocket hole tolerance over any 10 pitches ±0.2

0.35 ±0.05

16.00
2.00

4.00

11.4

1.75

7.6

11.5
24.0 ±0.2

RECOM
RSD-0505
xxxx

All dimensions in mm xx.xx ±0.1

RECOM
RSD-0505xxxx

1. 10 sprocket hole pitch cumulative tolerance ±0.20
2. All dimensions meet EIA-481-2 requirements
3. Component load per 13" reel : 500 pcs

RECOM
RSD-0505
xxxx

4. The diameter of disc center hole is 13.0mm

A-64

2014

www.recom-international.com

Tape and Reel (Suffix -R)

RSZ-xxxx, RTS-xxxx, R2S-xxxx, RTD-xxxx, R2D-xxxx
R-78Axx-xxSMD & R-78AAxx-xxSMD tape outline dimensions

15.5

Spocket hole Ø1.50+0.1/-0
Spocket hole tolerance over any 10 pitches ±0.2

0.5 ±0.05

20.00
2.00

4.00

12.5

1.75

9.9

11.5
24.0 ±0.3

RECOM
RSZ-0505
xxxx

All dimensions in mm xx.xx ±0.1
1. 10 sprocket hole pitch cumulative tolerance ±0.20
2. All dimensions meet EIA-481-2 requirements
3. Component load per 13" reel : 500 pcs

RECOM
RSZ-0505
xxxx

4. The diameter of disc center hole is 13.0mm

www.recom-international.com

RECOM
RSZ-0505
xxxx

2014

A-65