LTM8063
40VIN, 2A Silent SwitcherµModule Regulator
FEATURESDESCRIPTION

Low Noise Silent Switcher® Architecture
nn Wide Input Voltage Range: 3.2V to 40V
nn Wide Output Voltage Range: 0.8V to 15V
nn 2A Continuous Output Current at 12V , 5V
IN
OUT,
TA = 85°C
nn 2.5A Peak Current
nn Selectable Switching Frequency: 200kHz to 2.2MHz
nn External Synchronization
nn Configurable as an Inverter
nn 6.25mm × 4mm × 2.22mm BGA Package

The LTM®8063 is a 40VIN, 2A continuous, 2.5A peak, stepdown µModule® (power module) regulator. Included in
the package are the switching controller, power switches,
inductor, and all support components. Operating over an
input voltage range of 3.2V to 40V, the LTM8063 supports
an output voltage range of 0.8V to 15V and a switchingfrequency range of 200kHz to 2.2MHz, each set by a single
resistor. Only the input and output filter capacitors areneeded to finish the design.

nn

The low profile package enables utilization of unused
space on the bottom of PC boards for high density point ofload regulation. The LTM8063 is packaged in a thermallyenhanced, compact over-molded ball grid array (BGA) package suitable for automated assembly by standard surface
mount equipment. The LTM8063 is RoHS compliant.

APPLICATIONS
Automotive Battery Regulation
Power for Portable Products
nn Distributed Supply Regulation
nn Industrial Supplies
nn Wall Transformer Regulationnn
nn

All registered trademarks and trademarks are the property of their respective owners.

TYPICAL APPLICATION
Efficiency vs Load Current
95

5VOUT from 6.5VIN to 40VIN Step-Down Converter
VIN

LTM8063

85

RUN
1µF

VOUT
RT

27.4k
1.4MHz

GND

SYNC

FB

45.3k

22µF

VOUT
5V
2A
2.5A PEAK

8063 TA01a

PINS NOT USED IN THIS CIRCUIT: TR/SS, PG

EFFICIENCY (%)

VIN
6.5V TO 40V

75

65

55

12VIN
24VIN
36VIN
0

0.5

1
1.5
LOAD CURRENT (A)22.5
8063 TA01b

Rev C

Document Feedback

For more information www.analog.com

1

LTM8063
TABLE OF CONTENTS
Features............................................................................................................................. 1
Applications........................................................................................................................ 1
Typical Application................................................................................................................ 1
Description......................................................................................................................... 1
Absolute Maximum Ratings...................................................................................................... 3
Order Information.................................................................................................................. 3
Pin Configuration.................................................................................................................. 3
Electrical Characteristics......................................................................................................... 4
Typical Performance Characteristics........................................................................................... 5
Pin Functions......................................................................................................................11
Block Diagram.....................................................................................................................12
Operation..........................................................................................................................12
Applications Information........................................................................................................13
Typical Applications..............................................................................................................20
Package Photo....................................................................................................................21
Package Description.............................................................................................................21
Revision History..................................................................................................................23
Typical Application...............................................................................................................24
Related Parts......................................................................................................................24

Rev C

2

For more information www.analog.com

LTM8063
ABSOLUTE MAXIMUM RATINGSPIN CONFIGURATION(Notes 1, 2)

VIN, RUN, PG Voltage.................................................42V
VOUT Voltage..............................................................19V
FB, TR/SS Voltage.......................................................4V
SYNC Voltage...............................................................6V
Maximum Internal Temperature............................. 125°C
Storage Temperature.............................. –55°C to 125°C
Peak Reflow Solder Body Temperature.................. 260°C

GND

TOP VIEW
FB

TR/SS

SYNC

RUN

GND

A
B

PG
FB

BANK 2VIN

RTC
BANK 1D
GND
EF
BANK 3

VOUT

G
1

2

3

4

BGA PACKAGE
28-LEAD (6.25mm × 4mm × 2.22mm) BGA PACKAGETJMAX = 125°C, θJA = 41.5°C/W, θJCbottom = 13°C/W
θJCtop = 52.4°C/W, θJB = 16.3°C/W, WEIGHT = 0.14g
θ VALUES DETERMINED PER JEDEC51-9, 51-12

ORDER INFORMATIONPART MARKING*PART NUMBER
LTM8063EY#PBF
LTM8063IY#PBF
LTM8063IYTERMINAL FINISH
SAC305 (RoHS)
SnPb (63/37)

DEVICE
8063

FINISH CODE

PACKAGETYPE

MSL
RATING

BGA

3v

TEMPERATURE RANGE–40°C to 125°C•• Device temperature grade is indicated by a label on the shipping container. • This product is not recommended for second side reflow.
This product is moisture sensitive. For more information, go to• Pad or ball finish code is per IPC/JEDEC J-STD-609.
Recommended BGA PCB Assembly and Manufacturing Procedures.
• BGA Package and Tray Drawings

Rev C

For more information www.analog.com

3

LTM8063
ELECTRICAL CHARACTERISTICS

The l denotes the specifications which apply over the specified operating
temperature range, otherwise specifications are at TJ = 25°C. VIN = 12V, RUN = 2V, unless otherwise noted.
PARAMETERCONDITIONS

MIN

TYP

Minimum Input Voltage

VIN Rising

Output DC Voltage

RFB Open
RFB = 13.7kΩ, VIN = 40V

Peak Output DC Current

VOUT = 3.3V, fSW = 1MHz

Quiescent Current into VIN

RUN = 0V
No Load, SYNC = 0V, Not SwitchingLine Regulation

5.5V < VIN < 36V, IOUT = 1A

0.5

MAX
3.2

l

0.8
15

UNITS
V
V
V

2.5

A
3
8

µA
µA
%

Load Regulation

0.1A < IOUT < 2A

0.5%

Output Voltage Ripple

IOUT = 2A

15

mV

Switching Frequency

RT = 232kΩ, VIN = 8V
RT = 41.2kΩ
RT = 15.8kΩ

200
1
2.2

kHz
MHz
MHz

Voltage at FBl

RUN Threshold Voltage

760

774

0.9

RUN Current

786

mV

1.2

V

1

µA

TR/SS Current

TR/SS = 0V

2

µA

TR/SS Pull Down

TR/SS = 0.1V

300

Ω

PG Threshold Voltage at FB (Upper)

FB Falling (Note 5)

0.84

V

PG Threshold Voltage at FB (Lower)

FB Rising (Note 5)

0.7

V

PG Leakage Current

PG = 42V

PG Sink Current

PG = 0.1V

SYNC Threshold Voltage

Synchronization

0.4

1.5

SYNC Voltage

To Enable Spread Spectrum

2.9

4.2

V

SYNC Current

SYNC = 2V

5µA

Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: Unless otherwise noted, the absolute minimum voltage is zero.
Note 3: The LTM8063E is guaranteed to meet performance specifications
from 0°C to 125°C internal. Specifications over the full –40°C to
125°C internal operating temperature range are assured by design,
characterization and correlation with statistical process controls. The
LTM8063I is guaranteed to meet specifications over the full –40°C to
125°C internal operating temperature range. Note that the maximum
internal temperature is determined by specific operating conditions inconjunction with board layout, the rated package thermal resistance andother environmental factors.

1
150

µA
µA
V

Note 4: The LTM8063 contains overtemperature protection that is
intended to protect the device during momentary overload conditions. Theinternal temperature exceeds the maximum operating junction temperaturewhen the overtemperature protection is active. Continuous operation
above the specified maximum operating junction temperature may impair
device reliability.
Note 5: PG transitions from low to high.

Rev C

4

For more information www.analog.com

LTM8063
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted.
Efficiency, VOUT = 1V

80

60

50

40

60

0

0.5

1
1.5
LOAD CURRENT (A)

2

40

2.5

12VIN
24VIN
36VIN
0

0.5

1
1.5
LOAD CURRENT (A)

2

45

2.5

Efficiency, VOUT = 2V

75

80
EFFICIENCY (%)

75
EFFICIENCY (%)

90

65

55

55
12VIN
24VIN
36VIN
0

0.5

1
1.5
LOAD CURRENT (A)

2

45

2.5

95

80

0

0.5

1
1.5
LOAD CURRENT (A)

2

50

50

2.5

Efficiency, VOUT = 5V

95

EFFICIENCY (%)

EFFICIENCY (%)
0

0.5

1
1.5
LOAD CURRENT (A)

2

2.5

12VIN
24VIN
36VIN
0

0.5

75

55

1
1.5
LOAD CURRENT (A)2

2.5

Efficiency, VOUT = 8V

85

75

65

65
12VIN
24VIN
36VIN

2.5

8063 G06

85

60

2

70

8063 G05

Efficiency, VOUT = 3.3V

70

1
1.5
LOAD CURRENT (A)

60
12VIN
24VIN
36VIN

8063 G0490

0.5

Efficiency, VOUT = 2.5V

85

45

0

8063 G03

85

65

12VIN
24VIN
36VIN

8063 G02

Efficiency, VOUT = 1.8V

EFFICIENCY (%)

65

55

50
12VIN
24VIN
36VIN

Efficiency, VOUT = 1.5V

758063 G01

EFFICIENCY (%)

85

70
EFFICIENCY (%)

EFFICIENCY (%)

70

Efficiency, VOUT = 1.2V

EFFICIENCY (%)

80

12VIN
24VIN
36VIN
0

0.5

1
1.5
LOAD CURRENT (A)28063 G07

2.58063 G08

55

12VIN
24VIN
36VIN
0

0.5

1
1.5
LOAD CURRENT (A)22.5
8063 G09

Rev C

For more information www.analog.com

5

LTM8063
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted.
Efficiency, VOUT = 12V

95

80

75

65

75

0

0.5

1
1.5
LOAD CURRENT (A)

2

55

2.5

24VIN
36VIN
0

0.5

1
1.5
LOAD CURRENT (A)

80

70

70

EFFICIENCY (%)

EFFICIENCY (%)

EFFICIENCY (%)

80

60

12VIN
24VIN
0

0.5

1
1.5
LOAD CURRENT (A)

50

2

12VIN
24VIN
0

0.5
1
LOAD CURRENT (A)8063 G13

0.4

50

0

0.25
0.50
LOAD CURRENT (A)

50

1.5

0.75

2

Efficiency, VOUT = –12V

12VIN
24VIN
0

0.25
0.50
0.75
LOAD CURRENT (A)

0.4

0.2

0.1

0

0

0.5

1
1.5
LOAD CURRENT (A)28063 G16

1

Input vs Load Current,
VOUT = 1.2V

12VIN
24VIN
36VIN

0.3

2.5

8063 G15

INPUT CURRENT (A)INPUT CURRENT (A)EFFICIENCY (%)

80

12VIN
24VIN

1
1.5
LOAD CURRENT (A)60

Input vs Load Current, VOUT = 1V

60

0.5

8063 G14

Efficiency, VOUT = –15V

70

08063 G12

Efficiency, VOUT = –8V

60

12VIN
24VIN
36VIN

8063 G11

Efficiency, VOUT = –5V

70

50

60

50

2

8063 G10

80

70

65
24VIN
36VIN

55

Efficiency, VOUT = –3.3V

85
EFFICIENCY (%)

EFFICIENCY (%)

85

Efficiency, VOUT = 15V

EFFICIENCY (%)

95

2.5
8063 G17

12VIN
24VIN
36VIN

0.3

0.2

0.1

0

0

0.5

1
1.5
LOAD CURRENT (A)22.5
8063 G18

Rev C

6For more information www.analog.com

LTM8063
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted.
Input vs Load Current
VOUT = 1.5V
0.6

0.4

0.2

0

0

0.5

1
1.5
LOAD CURRENT (A)

2

0.6

12VIN
24VIN
36VIN

0.4

0.2

0

2.5

Input vs Load Current
VOUT = 2V

INPUT CURRENT (A)

12VIN
24VIN
36VIN
INPUT CURRENT (A)INPUT CURRENT (A)0.6

Input vs Load Current
VOUT = 1.8V

0

0.5

1
1.5
LOAD CURRENT (A)28063 G19

0.25

0

0

0.5

1
1.5
LOAD CURRENT (A)

2

0.8

0.4

0

2.5

2.0

12VIN
24VIN
36VIN
INPUT CURRENT (A)INPUT CURRENT (A)INPUT CURRENT (A)

1.2

0.50

0

0.5

1
1.5
LOAD CURRENT (A)28063 G22

0

0

0.5

1
1.5
LOAD CURRENT (A)

2

2.5

2

Input vs Load Current
VOUT = 8V
12VIN
24VIN
36VIN

0.5

0

0.5

1
1.5
LOAD CURRENT (A)28063 G24

1.00

24VIN
36VIN

0.5

0

0.5

1
1.5
LOAD CURRENT (A)8063 G25

2.5

Input vs Load Current
VOUT = –3.3V

1.0

0

2.5

1.0

0

2.5

INPUT CURRENT (A)INPUT CURRENT (A)INPUT CURRENT (A)

1.5

24VIN
36VIN

0.5

1
1.5
LOAD CURRENT (A)

1.5

Input vs Load Current
VOUT = 15V

1.0

0.5

8063 G23

Input vs Load Current
VOUT = 12V
1.5

08063 G21

Input vs Load Current
VOUT = 5V

12VIN
24VIN
36VIN

0.75

0.2

8063 G20

Input vs Load Current
VOUT = 3.3V
1.00

0.4

0

2.5

12VIN
24VIN
36VIN

2
8063 G26

12VIN
24VIN
36VIN

0.75

0.50

0.25

0

0

0.5

1
1.5
LOAD CURRENT (A)22.5
8063 G27

Rev C

For more information www.analog.com

7

LTM8063
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted.

0.80

0.40

0.5

1
1.5
LOAD CURRENT (A)

1.00

0.50

0

2

0

0.5
1
LOAD CURRENT (A)MAXIMUM LOAD CURRENT (A)INPUT CURRENT (A)

0.40

0.25
0.50
LOAD CURRENT (A)–3.3VOUT–5VOUT–8VOUT
0

10

20
30
INPUT VOLTAGE (V)

3

0

10

20
VIN (V)

0.50

0.25

0

40

30

40
8063 G34–12VOUT–15VOUT
0

10
20
INPUT VOLTAGE (V)

Derating, VOUT = 1.2V,
DC2494A Demo Board
3

0LFM

2

1

0

12VIN
24VIN
36VIN
0

25
50
75
100
AMBIENT TEMPERATURE (°C)

308063 G33

Derating, VOUT = 1V,
DC2494A Demo Board

MAXIMUM LOAD CURRENT (A)INPUT CURRENT (mA)

0

0.75

8063 G32

Input Current vs VIN
VOUT Short Circuited

1

Maximum Load Current vs VIN

18063 G31

300

0.25
0.50
0.75
LOAD CURRENT (A)

1.00

2

0

0.75

600

0

8063 G30

Maximum Load Current vs VIN

0.80

900

0

3

12VIN
24VIN

0

0.5

8063 G29

Input vs Load Current
VOUT = –15V

0

1.0

1.5

8063 G28

1.20

Input vs Load Current
VOUT = –12V
12VIN
24VIN

MAXIMUM LOAD CURRENT (A)

0

1.5

12VIN
24VIN

MAXIMUM LOAD CURRENT (A)0

Input vs Load Current
VOUT = –8V

INPUT CURRENT (A)

1.50

12VIN
24VIN
INPUT CURRENT (A)INPUT CURRENT (A)

1.20

Input vs Load Current
VOUT = –5V

1258063 G35

0LFM

2

1

0

12VIN
24VIN
36VIN
0

25
50
75
100
AMBIENT TEMPERATURE (°C)

1258063 G36

Rev C

8For more information www.analog.com

LTM8063
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted.
Derating, VOUT = 1.8V,
DC2494A Demo Board

Derating, VOUT = 1.5V,
DC2494A Demo Board
3

2

1

0

25
50
75
100
AMBIENT TEMPERATURE (°C)

125

2

1

0

12VIN
24VIN
36VIN
0

25
50
75
100
AMBIENT TEMPERATURE (°C)

8063 G37

3

12VIN
24VIN
36VIN

2

1

0

125

MAXIMUM LOAD CURRENT (A)MAXIMUM LOAD CURRENT (A)MAXIMUM LOAD CURRENT (A)

1

12VIN
24VIN
36VIN
0

25
50
75
100
AMBIENT TEMPERATURE (°C)

8063 G40

3

1

0

125

MAXIMUM LOAD CURRENT (A)

2

1
12VIN
24VIN
36VIN
25
50
75
100
AMBIENT TEMPERATURE (°C)

125

12VIN
24VIN
36VIN
0

25
50
75
100
AMBIENT TEMPERATURE (°C)

Derating, VOUT = 8V,
DC2494A Demo Board

2

1

0

12VIN
24VIN
36VIN
0

125
8063 G42

30 LFM
fSW = 2MHz

0 LFM
MAXIMUM LOAD CURRENT (A)2

Derating, VOUT = 5V,
DC2494A Demo Board

3

125

0 LFM
fSW = 2MHz

8063 G41

Derating, VOUT = 5V,
DC2494A Demo Board

0

25
50
75
100
AMBIENT TEMPERATURE (°C)

0 LFM

2

0

0

Derating, VOUT = 3.3V,
DC2494A Demo Board

3
0 LFM

25
50
75
100
AMBIENT TEMPERATURE (°C)

12VIN
24VIN
36VIN

8063 G39

Derating, VOUT = 3.3V,
DC2494A Demo Board

3

0

1

8063 G38

Derating, VOUT = 2.5V,
DC2494A Demo Board

0

0LFM

2

0

125

25
50
75
100
AMBIENT TEMPERATURE (°C)

8063 G43

0 LFM
MAXIMUM LOAD CURRENT (A)

0

12VIN
24VIN
36VIN

3

0LFM
MAXIMUM LOAD CURRENT (A)

0LFM
MAXIMUM LOAD CURRENT (A)MAXIMUM LOAD CURRENT (A)3

Derating, VOUT = 2V,
DC2494A Demo Board

125
8063 G44

2

1

0

12VIN
24VIN
36VIN
0

25
50
75
100
AMBIENT TEMPERATURE (°C)

1258063 G45

Rev C

For more information www.analog.com

9

LTM8063
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted.
Derating, VOUT = 12V,
DC2494A Demo Board

Derating, VOUT = 15V,
DC2494A Demo Board
1.5

1.5

2.0
0 LFM

1.0

0.5

24VIN
36VIN
0

25
50
75
100
AMBIENT TEMPERATURE (°C)

1.0

0.5

0

125
C)

24VIN
36VIN
0

25
50
75
100
AMBIENT TEMPERATURE (°C)

Derating, VOUT = –5V,
DC2494A Demo Board

0.5

0

125

0

25
50
75
100
AMBIENT TEMPERATURE (°C)

0.5

0.5
12VIN
24VIN

1.0

0.5

0

125
C)

0 LFM
MAXIMUM LOAD CURRENT (A)MAXIMUM LOAD CURRENT (A)

1.0

12VIN
24VIN
0

25
50
75
100
AMBIENT TEMPERATURE (°C)

8063 G49

0.4

0.3

0.2

0.1

0

125

12VIN
24VIN
0

8063 G50

0.5

25
50
75
100
AMBIENT TEMPERATURE (°C)

1258063 G51CISPR22 Class B Emissions
DC2494A Demo Board, VOUT = 5V,
C9 = 0.1µF, No EMI Filter, 1A Load

Derating, VOUT = –15V,
DC2494A Demo Board

125

Derating, VOUT = –12V,
DC2494A Demo Board
0 LFM

1.5

25
50
75
100
AMBIENT TEMPERATURE (°C)

12VIN
24VIN
36VIN

8063 G48

1.5
0 LFM

MAXIMUM LOAD CURRENT (A)

1.0

Derating, VOUT = –8V,
DC2494A Demo Board

2.0

0

1.5

8063 G47

8063 G46

00 LFM
MAXIMUM LOAD CURRENT (A)MAXIMUM LOAD CURRENT (A)MAXIMUM LOAD CURRENT (A)

0 LFM

0

Derating, VOUT = –3.3V,
DC2494A Demo Board

Dropout Voltage vs Load Current
VOUT = 5V

55

800

0.3

0.2

0.1

0
C)

25
50
75
100
AMBIENT TEMPERATURE (°C)

35
25
15
5

12VIN
24VIN
0

DROPOUT VOLTAGE (mV)45

0.4
AMPLITUDE (dBuV/m)

MAXIMUM LOAD CURRENT (A)

0 LFM

125

–5

HORIZONTALVERTICAL
0

200

400
600
FREQUENCY (MHz)800

8063 G52

1000
8063 G53

600

400

200

0

0

0.5

1
1.5
LOAD CURRENT (A)22.5
8063 G54

Rev C

10

For more information www.analog.com

LTM8063
PIN FUNCTIONSGND (Bank 1, A1, A4): Tie these GND pins to a local groundplane below the LTM8063 and the circuit components.
In most applications, the bulk of the heat flow out of the
LTM8063 is through these pads, so the printed circuitdesign has a large impact on the thermal performance ofthe part. See the PCB Layout and Thermal Considerations
sections for more details.
VIN (Bank 2): VIN supplies current to the LTM8063’s internal regulator and to the internal power switches. These
pins must be locally bypassed with an external, low ESR
capacitor; see Table 1 for recommended values.
VOUT (Bank 3): Power Output Pins. Apply the output filter
capacitor and the output load between these pins and
GND pins.
RUN (Pin B3): Pull the RUN pin below 0.9V to shut down
the LTM8063. Tie to 1.2V or more for normal operation. If
the shutdown feature is not used, tie this pin to the VIN pin.
RT (Pin C1): The RT pin is used to program the switchingfrequency of the LTM8063 by connecting a resistor fromthis pin to ground. The Applications Information section of
the data sheet includes a table to determine the resistancevalue based on the desired switching frequency. Minimize
capacitance at this pin. Do not drive this pin.
SYNC (Pin B2): External clock synchronization input
and operational mode. This pin programs four different
operating modes:
1. Burst Mode® Operation. Tie this pin to ground for Burst
Mode operation at low output loads—this will result inultralow quiescent current.

2. Pulse-skipping mode. Float this pin for pulse-skipping
mode. This mode offers full frequency operation down
to low output loads before pulse skipping occurs.
3. Spread spectrum mode. Tie this pin high (between
2.9V and 4.2V) for pulse-skipping mode with spread
spectrum modulation.
4. Synchronization mode. Drive this pin with a clock source
to synchronize to an external frequency. During synchronization the part will operate in pulse-skipping mode.
PG (Pin B1): The PG pin is the open-collector output of
an internal comparator. PG remains low until the FB pin
voltage is within about 10% of the final regulation voltage. The PG signal is valid when VIN is above 3.2V. If VIN
is above 3.2V and RUN is low, PG will drive low. If thisfunction is not used, leave this pin floating.
FB (Pin A2): The LTM8063 regulates its FB pin to 0.77V.
Connect the adjust resistor from this pin to ground.
The value of RFB is given by the equation RFB = 192.73/(VOUT – 0.774), where RFB is in kΩ.
TR/SS (Pin A3): The TR/SS pin is used to provide a softstart or tracking function. The internal 2μA pull-up current
in combination with an external capacitor tied to this pin
creates a voltage ramp. If TR/SS is less than about 0.77V,
the FB voltage tracks to this value. The soft-start ramp time
is approximated by the equation t = 0.39 • C where C isin μF. For tracking, tie a resistor divider to this pin from thetracked output. This pin is pulled to ground with an internal
MOSFET during shutdown and fault conditions; use a series
resistor if driving from a low impedance output. This pin
may be left floating if the tracking function is not needed.

Rev C

For more information www.analog.com

11

LTM8063
BLOCK DIAGRAM
LTM8063 Block Diagram
VIN

0.2µF

CURRENT
MODE
CONTROLLER

1.5µH

VOUT
249k

10pF
3.3nF

GND

FB

RUN
TR/SS

PG

SYNC
RT

8063 BDOPERATION
The LTM8063 is a stand-alone non-isolated step-down
switching DC/DC power supply that can deliver up to
2.5A. The continuous current is determined by the internal
operating temperature. It provides a precisely regulated
output voltage programmable via one external resistor
from 0.8V to 15V. The input voltage range is 3.2V to 40V.
Given that the LTM8063 is a step-down converter, makesure that the input voltage is high enough to support thedesired output voltage and load current. A simplified Block
Diagram is given above.
The LTM8063 contains a current mode controller, powerswitching elements, power inductor and a modest amountof input and output capacitance. The LTM8063 is a fixed
frequency PWM regulator. The switching frequency is set
by simply connecting the appropriate resistor value fromthe RT pin to GND.
The RUN pin is used to place the LTM8063 in shutdown,
disconnecting the output and reducing the input current
to a few µA.
To enhance efficiency, the LTM8063 automatically switches
to Burst Mode operation in light or no load situations.
Between bursts, all circuitry associated with controllingthe output switch is shut down reducing the input supply
current to just a few µA.

The oscillator reduces the LTM8063’s operating frequency
when the voltage at the FB pin is low. This frequency foldback helps to control the output current during start-up
and overload.
The TR/SS node acts as an auxiliary input to the error amplifier. The voltage at FB servos to the TR/SS voltage until
TR/SS goes above 0.77V. Soft-start is implemented bygenerating a voltage ramp at the TR/SS pin using an external
capacitor which is charged by an internal constant current.
Alternatively, driving the TR/SS pin with a signal sourceor resistive network provides a tracking function. Do not
drive the TR/SS pin with a low impedance voltage source.
See the Applications Information section for more details.
The LTM8063 contains a power good comparator whichtrips when the FB pin is at about 90% to 110% of its regulated value. The PG output is an open-drain transistor thatis off when the output is in regulation, allowing an external
resistor to pull the PG pin high. The PG signal is valid when
VIN is above 3.2V. If VIN is above 3.2V and RUN is low, PG
will drive low.
The LTM8063 is equipped with a thermal shutdown that
inhibits power switching at high junction temperatures.
The activation threshold of this function is above the maximum temperature rating to avoid interfering with normal
operation, so prolonged or repetitive operation under acondition in which the thermal shutdown activates may
damage or impair the reliability of the device
Rev C

12

For more information www.analog.com

LTM8063
APPLICATIONS INFORMATION
For most applications, the design process is straightforward, summarized as follows:
1. Look at Table 1 and find the row that has the desired
input range and output voltage.
2. Apply the recommended, CIN, COUT, RFB and RT values.
3. Apply the CFF (from VOUT to FB) as required.
While these component combinations have been tested
for proper operation, it is incumbent upon the user toverify proper operation over the intended system’s line,
load and environmental conditions. Bear in mind that the
maximum output current is limited by junction tempera-ture, the relationship between the input and output voltage
magnitude and polarity and other factors. Please refer tothe graphs in the Typical Performance Characteristics
section for guidance.
The maximum frequency (and attendant RT value) at
which the LTM8063 should be allowed to switch is given
in Table 1 in the Maximum fSW column, while the recommended frequency (and RT value) for optimal efficiency
over the given input condition is given in the fSW column.
There are additional conditions that must be satisfied if
the synchronization function is used. Please refer to the
Synchronization section for details.

Table 1. Recommended Component Values and Configuration (TA = 25°C)
VIN

VOUT

RFB
(kΩ)

CIN2

COUT

CFF

fSW

RT
(kΩ)

MAX fSWMIN RT(kΩ)

3.2 to 40

0.77V

Open

1µF 50V 0805 X5R

100µF 4V 0805 X5R

27pF

600kHz73.2

600kHz73.2

3.2 to 40

1.0V

845

1µF 50V 0805 X5R

100µF 4V 0805 X5R

10pF

700kHz60.4

725kHz59

3.2 to 40

1.2V

453

1µF 50V 0805 X5R

100µF 4V 0805 X5R

800kHz52.3

850kHz48.7

3.2 to 40

1.5V

267

1µF 50V 0805 X5R

100µF 4V 0805 X5R

800kHz

52.3

1MHz

41.2

3.2 to 40

1.8V

187

1µF 50V 0805 X5R

100µF 4V 0805 X5R

900kHz47.5

1.2MHz33.2

3.3 to 40V1

2.0V

154

1µF 50V 0805 X5R

100µF 4V 0805 X5R

1MHz

41.2

1.3MHz29.4

3.8 to 40V1

2.5V

113

1µF 50V 0805 X5R

47µF 4V 0805 X5R

1.2MHz33.2

1.6MHz23.7

5 to 40V1

3.3V

75

1µF 50V 0805 X5R

47µF 4V 0805 X5R

1.2MHz

33.2

2MHz

18.2

6.5 to 40V1

5V

45.3

1µF 50V 0805 X5R

22µF 6.3V 0805 X5R

1.4MHz27.4

2.2MHz15.8

10.5 to 40V1

8V

26.7

1µF 50V 0805 X5R

10µF 10V 0805 X5R

1.8MHz20.5

2.2MHz15.8

18.5 to 40V1

12V

17.4

1µF 50V 0805 X5R

10µF 16V 0805 X7S

1.8MHz20.5

2.2MHz15.8

22 to 40V1

15V

13.7

1µF 50V 0805 X5R

10µF 25V 1206 X7R

2MHz

18.2

2.2MHz15.8

3.2 to 36V1

–3.3V

75

1µF 50V 0805 X5R

47µF 4V 0805 X5R

1.2MHz

33.2

2MHz

18.2

3.2 to 35V1

–5V

45.3

1µF 50V 0805 X5R

22µF 6.3V 0805 X5R

1.4MHz27.4

2.2MHz15.8

3.2 to 32V1

–8V

26.7

1µF 50V 0805 X5R

10µF 10V 0805 X5R

1.8MHz20.5

2.2MHz15.8

3.2 to 28V1

–12V

17.4

1µF 50V 0805 X5R

10µF 16V 0805 X7S

1.8MHz20.5

2.2MHz15.8

3.2 to 25V1

–15V

13.7

1µF 50V 0805 X5R

10µF 25V 1206 X7R

2MHz

18.2

2.2MHz15.8

1. The LTM8063 may be capable of lower input voltages but may skip switching cycles.
2. An input bulk capacitor is required

Rev C

For more information www.analog.com

13

LTM8063
APPLICATIONS INFORMATION
Capacitor Selection Considerations

Frequency Selection

The CIN and COUT capacitor values in Table 1 are theminimum recommended values for the associated operating conditions. Applying capacitor values below thoseindicated in Table 1 is not recommended and may resultin undesirable operation. Using larger values is generally
acceptable, and can yield improved dynamic response, if
it is necessary. Again, it is incumbent upon the user toverify proper operation over the intended system’s line,
load and environmental conditions.

The LTM8063 uses a constant frequency PWM architecture that can be programmed to switch from 200kHz
to 2.2MHz by using a resistor tied from the RT pin toground. Table 2 provides a list of RT resistor values andtheir resultant frequencies.
Table 2. SW Frequency vs RT ValuefSW (MHz)RT (kΩ)

0.2

232

0.3

150

0.4

110

0.5

88.7

0.6

73.2

0.7

60.4

0.8

52.3

1.0

41.2

1.2

33.2

1.4

27.4

1.6

23.7

1.8

20.5

2.0

18.2

2.2

15.8

Ceramic capacitors are small, robust and have very low
ESR. However, not all ceramic capacitors are suitable.
X5R and X7R types are stable over temperature and applied voltage and give dependable service. Other types,
including Y5V and Z5U have very large temperature andvoltage coefficients of capacitance. In an application circuit they may have only a small fraction of their nominal
capacitance resulting in much higher output voltage ripple
than expected.
Ceramic capacitors are also piezoelectric. In Burst Modeoperation, the LTM8063’s switching frequency depends
on the load current, and can excite a ceramic capacitor
at audio frequencies, generating audible noise. Since theLTM8063 operates at a lower current limit during Burst
Mode operation, the noise is typically very quiet to acasual ear.
If this audible noise is unacceptable, use a high performance electrolytic capacitor at the output. It may also bea parallel combination of a ceramic capacitor and a low
cost electrolytic capacitor.
A final precaution regarding ceramic capacitors concerns
the maximum input voltage rating of the LTM8063. A
ceramic input capacitor combined with trace or cableinductance forms a high-Q (underdamped) tank circuit.
If the LTM8063 circuit is plugged into a live supply, theinput voltage can ring to twice its nominal value, possibly exceeding the device’s rating. This situation is easily
avoided; see the Hot-Plugging Safely section.

Operating Frequency Trade-Offs
It is recommended that the user apply the optimal RT
value given in Table 1 for the input and output operating
condition. System level or other considerations, however,
may necessitate another operating frequency. While theLTM8063 is flexible enough to accommodate a wide
range of operating frequencies, a haphazardly chosen
one may result in undesirable operation under certain
operating or fault conditions. A frequency that is toohigh can reduce efficiency, generate excessive heat oreven damage the LTM8063 if the output is overloaded
or short-circuited. A frequency that is too low can resultin a final design that has too much output ripple or toolarge of an output capacitor.
Maximum Load
The maximum practical continuous load that the LTM8063
can drive, while rated at 2A, actually depends upon boththe internal current limit and the internal temperature.
Rev C

14

For more information www.analog.com

LTM8063
APPLICATIONS INFORMATION
The internal current limit is designed to prevent damage
to the LTM8063 in the case of overload or short-circuit.
The internal temperature of the LTM8063 depends upon
operating conditions such as the ambient temperature,
the power delivered, and the heat sinking capability ofthe system. For example, if the LTM8063 is configured
to regulate at 1.2V, it may continuously deliver 2.5A from
12VIN if the ambient temperature is controlled to less than
55°C. This is higher than the 2A continuous rating. Please
see the “Derating, VOUT = 1.2V” curve in the Typical Performance Characteristics section. Similarly, if the output
voltage is 15V and the ambient temperature is 100°C, theLTM8063 will deliver less than 100mA from 36VIN, whichis less than the 2A continuous rating.
Load Sharing
The LTM8063 is not designed to load share.
Burst Mode Operation
To enhance efficiency at light loads, the LTM8063 automatically switches to Burst Mode operation which keeps
the output capacitor charged to the proper voltage while
minimizing the input quiescent current. During Burst
Mode operation, the LTM8063 delivers single cycle burstsof current to the output capacitor followed by sleep periods
where most of the internal circuitry is powered off andenergy is delivered to the load by the output capacitor.
During the sleep time, VIN quiescent current is greatly
reduced, so, as the load current decreases towards a noload condition, the percentage of time that the LTM8063
operates in sleep mode increases and the average input
current is greatly reduced, resulting in higher light load
efficiency.
Burst Mode operation is enabled by tying SYNC to GND.
Minimum Input Voltage
The LTM8063 is a step-down converter, so a minimum
amount of headroom is required to keep the output inregulation. Keep the input above 3.2V to ensure proper
operation. Voltage transients or ripple valleys that cause
the input to fall below 3.2V may turn off the LTM8063.

Output Voltage Tracking and Soft-Start
The LTM8063 allows the user to adjust its output voltage
ramp rate by means of the TR/SS pin. An internal 2μA pulls
up the TR/SS pin to about 2.4V. Putting an external capacitor on TR/SS enables soft starting the output to reduce
current surges on the input supply. During the soft-start
ramp the output voltage will proportionally track the TR/
SS pin voltage. For output tracking applications, TR/SS
can be externally driven by another voltage source. From
0V to 0.77V, the TR/SS voltage will override the internal
0.77V reference input to the error amplifier, thus regulating the FB pin voltage to that of the TR/SS pin. When TR/
SS is above 0.77V, tracking is disabled and the feedback
voltage will regulate to the internal reference voltage. The
TR/SS pin may be left floating if the function is not needed.
An active pull-down circuit is connected to the TR/SS pin
which will discharge the external soft-start capacitor in
the case of fault conditions and restart the ramp when thefaults are cleared. Fault conditions that clear the soft-startcapacitor are the RUN pin transitioning low, VIN voltage
falling too low, or thermal shutdown.
Pre-Biased Output
As discussed in the Output Voltage Tracking and SoftStart section, the LTM8063 regulates the output to theFB voltage determined by the TR/SS pin whenever TR/
SS is less than 0.77V. If the LTM8063 output is higher
than the target output voltage, the LTM8063 will attempt
to regulate the output to the target voltage by returning asmall amount of energy back to the input supply. If there
is nothing loading the input supply, its voltage may rise.
Take care that it does not rise so high that the input voltage
exceeds the absolute maximum rating of the LTM8063.
Frequency Foldback
The LTM8063 is equipped with frequency foldback whichacts to reduce the thermal and energy stress on the internal
power elements during a short circuit or output overload
condition. If the LTM8063 detects that the output has
fallen out of regulation, the switching frequency is reduced
as a function of how far the output is below the target
voltage. This in turn limits the amount of energy that can
Rev C

For more information www.analog.com

15

LTM8063
APPLICATIONS INFORMATION
be delivered to the load under fault. During the start-up
time, frequency foldback is also active to limit the energy
delivered to the potentially large output capacitance ofthe load. When a clock is applied to the SYNC pin, theSYNC pin is floated or held high, the frequency foldback
is disabled, and the switching frequency will slow down
only during overcurrent conditions.

the LTM8063 is programmed to 2MHz, the frequency willvary from 2MHz to 2.4MHz at a 3kHz rate. When spread
spectrum operation is selected, Burst Mode operation isdisabled, and the part will run in pulse-skipping mode.
The LTM8063 does not operate in forced continuous mode
regardless of SYNC signal.
Negative Output

Synchronization
To select low ripple Burst Mode operation, tie the SYNC
pin below about 0.4V (this can be ground or a logic low
output). To synchronize the LTM8063 oscillator to an
external frequency, connect a square wave (with about
20% to 80% duty cycle) to the SYNC pin. The squarewave amplitude should have valleys that are below 0.4V
and peaks above 1.5V.
The LTM8063 will not enter Burst Mode operation at low
output loads while synchronized to an external clock, butinstead will pulse skip to maintain regulation. The LTM8063
may be synchronized over a 200kHz to 2.2MHz range.
The RT resistor should be chosen to set the switchingfrequency equal to or below the lowest synchronization
input. For example, if the synchronization signal will be
500kHz and higher, the RT should be selected for 500kHz.
For some applications it is desirable for the LTM8063 tooperate in pulse-skipping mode, offering two major differences from Burst Mode operation. The first is that theclock stays awake at all times and all switching cycles
are aligned to the clock. The second is that full switchingfrequency is reached at lower output load than in Burst
Mode operation. These two differences come at the expenseof increased quiescent current. To enable pulse-skipping
mode, the SYNC pin is floated.
The LTM8063 features spread spectrum operation tofurther reduce EMI/EMC emissions. To enable spread
spectrum operation, apply between 2.9V and 4.2V to the
SYNC pin. In this mode, triangular frequency modulation
is used to vary the switching frequency between the value
programmed by RT to about 20% higher than that value.
The modulation frequency is about 3kHz. For example, when

The LTM8063 is capable of generating a negative output
voltage by connecting its VOUT to system GND and the
LTM8063 GND to the negative voltage rail. An exampleof this is shown in the Typical Applications section. The
most versatile way to generate a negative output is touse a dedicated regulator that was designed to generatea negative voltage, but using a buck regulator like theLTM8063 to generate a negative voltage is a simple andcost effective solution, as long as certain restrictions are
kept in mind.
Figure 1 shows a typical negative output voltage application.
Note that LTM8063 VOUT is tied to system GND and input
power is applied from VIN to LTM8063 VOUT. As a result,the LTM8063 is not behaving as a true buck regulator,
and the maximum output current depends upon the input
voltage. In the example shown in the Typical Applications
section, there is an attending graph that shows how muchcurrent the LTM8063 can deliver for given input voltages.
VIN
VIN

VOUT
LTM8063
GND
NEGATIVEOUTPUT VOLTAGE
8063 F01

Figure 1. The LTM8063 Can Be Used to Generate a Negative
Voltage

Note that this configuration requires that any load current
transient will directly impress the transient voltage onto
the LTM8063 GND, as shown in Figure 2, so fast loadtransients can disrupt the LTM8063’s operation or evencause damage.
Rev C

16

For more information www.analog.com

LTM8063
APPLICATIONS INFORMATION
VIN
VIN

VOUT
LTM8063
GND

FAST LOAD
TRANSIENTOUTPUT TRANSIENTRESPONSE

8063 F02

Figure 2. Any Output Voltage Transient Appears on LTM8063 GND

The CIN and COUT capacitors in Figure 3 form an AC divider
at the negative output voltage node. If VIN is hot-plugged
or rises quickly, the resultant VOUT will be a positive transient, which may be unhealthy for the application load.
An anti-parallel Schottky diode may be able to prevent
this positive transient from damaging the load. The location of this Schottky diode is important. For example, ina system where the LTM8063 is far away from the load,
placing the Schottky diode closest to the most sensitive
load component may be the best design choice. Carefully
evaluate whether the negative buck configuration is suitable for the application.

or because it is tied to VIN), then the LTM8063’s internal
circuitry pulls its quiescent current through its internal
power switch. This is fine if your system can tolerate a
few milliamps in this state. If you ground the RUN pin, theinternal current drops to essentially zero. However, if the
VIN pin is grounded while the output is held high, parasitic
diodes inside the LTM8063 can pull large currents fromthe output through the VIN pin. Figure 4 shows a circuitthat runs only when the input voltage is present and that
protects against a shorted or reversed input.
VIN

VIN
LTM8063RUN
8063 F04

Figure 4. The Input Diode Prevents a Shorted Input from
Discharging a Backup Battery Tied to the Output. It Also
Protects the Circuit from a Reversed Input. The LTM8063
Runs Only When the Input Is Present

PCB Layout
FAST VIN
TRANSIENTOUTPUT EXPERIENCES
A POSITIVE TRANSIENT

VIN
VIN
CIN

VOUT
LTM8063COUT

GND
AC DIVIDEROPTIONALSCHOTTKY
DIODE

Most of the headaches associated with PCB layout havebeen alleviated or even eliminated by the high level ofintegration of the LTM8063. The LTM8063 is nevertheless a switching power supply, and care must be taken tominimize EMI and ensure proper operation. Even with thehigh level of integration, you may fail to achieve specified
operation with a haphazard or poor layout. See Figure 5
for a suggested layout. Ensure that the grounding andheat sinking are acceptable.

8063 F03

Figure 3. A Schottky Diode Can Limit the Transient Caused
by a Fast Rising VIN to Safe Levels

Shorted Input Protection
Care needs to be taken in systems where the output is heldhigh when the input to the LTM8063 is absent. This may
occur in battery charging applications or in battery backup
systems where a battery or some other supply is diode
ORed with the LTM8063’s output. If the VIN pin is allowed
to float and the RUN pin is held high (either by a logic signal

A few rules to keep in mind are:
1. Place CFF, RFB and RT as close as possible to theirrespective pins.
2. Place the CIN capacitor as close as possible to the VIN
and GND connection of the LTM8063.
3. Place the COUT capacitor as close as possible to the
VOUT and GND connection of the LTM8063.
4. Place the CIN and COUT capacitors such that their groundcurrents flow directly adjacent to or underneath the
LTM8063.
Rev C

For more information www.analog.com

17

LTM8063
APPLICATIONS INFORMATION
5. Connect all of the GND connections to as large a copperpour or plane area as possible on the top layer. Avoid
breaking the ground connection between the external
components and the LTM8063.
6. Use vias to connect the GND copper area to the board’s
internal ground planes. Liberally distribute these GND vias
to provide both a good ground connection and thermal
path to the internal planes of the printed circuit board. Pay
attention to the location and density of the thermal vias in
Figure 5. The LTM8063 can benefit from the heat-sinking
afforded by vias that connect to internal GND planes atthese locations, due to their proximity to internal power
handling components. The optimum number of thermal
vias depends upon the printed circuit board design.
For example, a board might use very small via holes. It
should employ more thermal vias than a board that uses
larger holes.

complete discussion). The low loss ceramic capacitor
combined with stray inductance in series with the powersource forms an underdamped tank circuit, and the voltage at the VIN pin of the LTM8063 can ring to more than
twice the nominal input voltage, possibly exceeding the
LTM8063’s rating and damaging the part. If the input supply
is poorly controlled or the LTM8063 is hot-plugged into anenergized supply, the input network should be designed
to prevent this overshoot. This can be accomplished byinstalling a small resistor in series to VIN, but the mostpopular method of controlling input voltage overshoot is
add an electrolytic bulk cap to the VIN net. This capacitor’s
relatively high equivalent series resistance damps the circuitand eliminates the voltage overshoot. The extra capacitor
improves low frequency ripple filtering and can slightly
improve the efficiency of the circuit, though it is likely tobe the largest component in the circuit.
Thermal Considerations

CIN

GND

VIN

TR/SS RUN
FB

GND

SYNC
PG

VOUT

RT

GND

COUT

GND/THERMAL VIAS

8063 F05

Figure 5. Layout Showing Suggested External
Components, GND Plane and Thermal Vias

Hot-Plugging Safely
The small size, robustness and low impedance of ceramic
capacitors make them an attractive option for the input
bypass capacitor of LTM8063. However, these capacitors
can cause problems if the LTM8063 is plugged into a live
supply (see Linear Technology Application Note 88 for a

The LTM8063 output current may need to be derated if it
is required to operate in a high ambient temperature. The
amount of current derating is dependent upon the input
voltage, output power and ambient temperature. The
derating curves given in the Typical Performance Characteristics section can be used as a guide. These curves
were generated by the LTM8063 mounted to a 58cm2
4-layer FR4 printed circuit board. Boards of other sizes
and layer count can exhibit different thermal behavior, so
it is incumbent upon the user to verify proper operation
over the intended system’s line, load and environmental
operating conditions.
For increased accuracy and fidelity to the actual application, many designers use FEA (Finite Element Analysis)
to predict thermal performance. To that end, Page 2 ofthe data sheet typically gives four thermal coefficients:
θJA – Thermal resistance from junction to ambientθJCbottom – Thermal resistance from junction to thebottom of the product caseθJCtop – Thermal resistance from junction to top of the
product case
θJB – Thermal resistance from junction to the printed
circuit board.
Rev C

18

For more information www.analog.com

LTM8063
APPLICATIONS INFORMATION
While the meaning of each of these coefficients may
seem to be intuitive, JEDEC has defined each to avoid
confusion and inconsistency. These definitions are given
in JESD 51-12, and are quoted or paraphrased below:
θJA is the natural convection junction-to-ambient air
thermal resistance measured in a one cubic foot sealed
enclosure. This environment is sometimes referred to as“still air” although natural convection causes the air tomove. This value is determined with the part mounted toa JESD 51-9 defined test board, which does not reflect anactual application or viable operating condition.
θJCbottom is the junction-to-board thermal resistance withall of the component power dissipation flowing through thebottom of the package. In the typical µModule regulator,
the bulk of the heat flows out the bottom of the package,
but there is always heat flow out into the ambient environment. As a result, this thermal resistance value may
be useful for comparing packages but the test conditions
don’t generally match the user’s application.
θJCtop is determined with nearly all of the component power
dissipation flowing through the top of the package. As theelectrical connections of the typical µModule regulator areon the bottom of the package, it is rare for an application
to operate such that most of the heat flows from the junction to the top of the part. As in the case of θJCbottom, thisvalue may be useful for comparing packages but the test
conditions don’t generally match the user’s application.
θJB is the junction-to-board thermal resistance where
almost all of the heat flows through the bottom of theµModule regulator and into the board, and is really thesum of the θJCbottom and the thermal resistance of thebottom of the part through the solder joints and through a
portion of the board. The board temperature is measured
a specified distance from the package, using a two sided,
two layer board. This board is described in JESD 51-9.
Given these definitions, it should now be apparent that noneof these thermal coefficients reflects an actual physicaloperating condition of a µModule regulator. Thus, noneof them can be individually used to accurately predict thethermal performance of the product. Likewise, it would
be inappropriate to attempt to use any one coefficient tocorrelate to the junction temperature vs load graphs givenin the product’s data sheet. The only appropriate way to
use the coefficients is when running a detailed thermal
analysis, such as FEA, which considers all of the thermal
resistances simultaneously.
A simplified graphical representation of these thermal
resistances is given in Figure 6. The blue resistances arecontained within the µModule regulator, and the green
are outside.
The die temperature of the LTM8063 must be lower thanthe maximum rating, so care should be taken in the layoutof the circuit to ensure good heat sinking of the LTM8063.
The bulk of the heat flow out of the LTM8063 is throughthe bottom of the package and the pads into the printed
circuit board. Consequently a poor printed circuit board
design can cause excessive heating, resulting in impaired
performance or reliability. Please refer to the PCB Layout
section for printed circuit board design suggestions.

JUNCTION-TO-AMBIENT RESISTANCE (JESD 51-9 DEFINED BOARD)
JUNCTION-TO-CASE (TOP)RESISTANCE

JUNCTION

CASE (TOP)-TO-AMBIENTRESISTANCE

JUNCTION-TO-BOARD RESISTANCE
JUNCTION-TO-CASE
CASE (BOTTOM)-TO-BOARD
RESISTANCE(BOTTOM) RESISTANCEAMBIENTBOARD-TO-AMBIENTRESISTANCE

8063 F06µMODULE DEVICE

Figure 6. Simplified Graphical Representation of the Thermal Resistance Between the Device Junction and Ambient
Rev C

For more information www.analog.com

19

LTM8063
TYPICAL APPLICATIONS
1.2VOUT from 3.2VIN to 40VIN Step-Down Converter
VIN

VIN
3.2V TO 40V
1µF
X5R
0805

LTM8063

RUN

VOUT
1.2V
100µF 2.3A
X5R 2.5A PEAK
0805

VOUT
RT

52.3k
800kHz

GND

SYNC

FB

453k

8063 TA02

PINS NOT USED IN THIS CIRCUIT: TR/SS, PG

3.3VOUT from 5VIN to 40VIN Step-Down Converter
VIN

VIN*
5V TO 40V
1µF
X5R
0805

LTM8063

RUN

VOUT
3.3V
2.1A
2.5A PEAK

VOUT
RT

33.2k
1.2MHz

GND

SYNC

FB

47µF
X5R
0805

75k

8063 TA03

PINS NOT USED IN THIS CIRCUIT: TR/SS, PG*VIN MAY BE AS LOW AS 3.6V WITH OFF-CYCLE SKIPPING–5VOUT from 3.2VIN to 35VIN Positive to Negative Converter
Maximum Load Current vs VIN

VIN

+

4.7µF
OPTIONAL
BULK CAP

1µF
X5R
0805

LTM8063

2.5

RUN
VOUT
RT

27.4k
1.4MHzPINS NOT USED IN THIS CIRCUIT: TR/SS, PG

FB
GND

SYNC

45.3k

22µF
X5R
0805
VOUT
–5V
8063 TA04a

MAXIMUM LOAD CURRENT (A)

VIN
3.2V
TO 35V

2.0

1.5

1.0

0.5

0

10

20
30
INPUT VOLTAGE (V)408063 TA04b

Rev C

20

For more information www.analog.com

LTM8063
PACKAGE PHOTO

PACKAGE DESCRIPTION
Table 3. LTM8063 Pinout (Sorted by Pin Number)
PIN

PIN NAME

PIN

PIN NAME

PIN

PIN NAME

PIN

PIN NAME

PIN

PIN NAME

PIN

PIN NAME

PIN

PIN NAME

A1

GND

B1

PG

C1

RT

D1

GND

E1

GND

F1

VOUT

G1

VOUT

A2

FB

B2

SYNC

C2

GND

D2

GND

E2

GND

F2

VOUT

G2

VOUT

A3

TR/SS

B3

RUN

C3

GND

D3

GND

E3

GND

F3

VOUT

G3

VOUT

A4

GND

B4

VIN

C4

VIN

D4

GND

E4

GND

F4

VOUT

G4

VOUT

Rev C

For more information www.analog.com

21

LTM8063
PACKAGE DESCRIPTIONBGA Package
28-Lead (6.25mm × 4mm × 2.22mm)

Z(Reference LTC DWG # 05-08-1517 Rev A)
A1

2×

A

DETAIL A

Z

ccc Z

4

A2

aaa Z

3

2

SEE NOTES
6

1

PIN 1

A

b1

PIN “A1”CORNER

MOLD
CAP

4

b

B

SUBSTRATE// bbb Z

D

C

H1

H2

F

D
E

DETAIL B

FeØb (28 PLACES)X

G

DETAIL B
PACKAGE SIDE VIEW

2. ALL DIMENSIONS ARE IN MILLIMETERS

1.2

0.4

0.4

1.2

0.000

DIMENSIONS

0.40 ±0.025 Ø 28x

2.4
1.6
0.8
0.000
0.8
1.6
2.4

SUGGESTED PCB LAYOUTTOP VIEW

NOM
2.22
0.40
1.82
0.50
0.40
6.25
4.00
0.80
4.80
2.40
0.32
1.50

MAX
2.42
0.50
1.92
0.55
0.43

NOTES

3

BALL DESIGNATION PER JEP95

4

DETAILS OF PIN #1 IDENTIFIER ARE OPTIONAL,
BUT MUST BE LOCATED WITHIN THE ZONE INDICATED.
THE PIN #1 IDENTIFIER MAY BE EITHER A MOLD OR
MARKED FEATURE

BALL HT

5. PRIMARY DATUM -Z- IS SEATING PLANE

BALL DIMENSIONPAD DIMENSIONSUBSTRATE THK
0.37
MOLD CAP HT
1.55
0.15
0.10
0.20
0.15
0.08
TOTAL NUMBER OF BALLS: 28

0.27
1.45

3

NOTES:
1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994

DETAIL A

MIN
2.02
0.30
1.72
0.45
0.37

SEE NOTESPACKAGE BOTTOM VIEW

2×

PACKAGE TOP VIEWSYMBOL
A
A1
A2
b
b1
D
E
e
F
G
H1
H2
aaa
bbb
ccc
ddd
eee

e

b

Y

E
aaa Z

G

ddd M Z X Y
eee M Z

6COMPONENTPIN “A1”

TRAY PIN 1
BEVEL

!

PACKAGE ROW AND COLUMN LABELING MAY VARY
AMONG µModule PRODUCTS. REVIEW EACH PACKAGELAYOUT CAREFULLYLTMXXXXXXµModule

PACKAGE IN TRAY LOADING ORIENTATIONBGA 28 0517 REV A

Rev C

22

For more information www.analog.com

LTM8063
REVISION HISTORY
REV

DATE

DESCRIPTION

A

02/18

Initial cap sentence (e.g.: Update to curve G04 in the Typical Performance Characteristics section).

4, 5

B

02/18

C

06/19

PAGE NUMBER

Changed IOUT from 2.5A to 2A for Output Voltage Ripple test.

3

Added VIN = 8V to Switching Frequency consideration.

3

Changed 2.5A to 2A in first paragraph.

15

Corrected pin name of pin B2 from FB to PG.

18

Changed θJA from 36.5°C/W to 41.5°C/W.

2

Changed θJCbottom from 10.4°C/W to 13°C/W.

2

Changed θJCtop from 37.1°C/W to 52.4°C/W.

2

Changed θJB from 10.8°C/W to 16.3°C/W.

2

Added LTM8063IY SnPb to Order Information.

2

Changed VIN transient to rising edge.

17

Rev C

Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog
Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications
subject to change without notice. No license For
is granted
implication orotherwise under any patent or patent rights of Analog Devices.
more byinformationwww.analog.com

23

LTM8063
TYPICAL APPLICATION
12VOUT from 18.5VIN to 40VIN Step Down Converter
VIN

VIN*
18.5V TO 40V
1µF
X5R
0805

LTM8063

RUN
VOUT
RT

20.5k
1.8MHz

GND

SYNC

FB

17.4k

10µF
X7S
0805

VOUT
12V
0.5A
2.2A PEAK

8063 TA05

PINS NOT USED IN THIS CIRCUIT: TR/SS, PG*VIN MAY BE AS LOW AS 12.6V WITH OFF-CYCLE SKIPPINGDESIGN RESOURCESSUBJECTDESCRIPTIONµModule Design and Manufacturing Resources

Design:• Selector Guides• Demo Boards and Gerber Files• Free Simulation ToolsµModule Regulator Products Search

1. Sort table of products by parameters and download the result as a spread sheet.

Manufacturing:• Quick Start Guide• PCB Design, Assembly and Manufacturing Guidelines• Package and Board Level Reliability

2. Search using the Quick Power Search parametric table.

Digital Power System Management

Analog Devices’ family of digital power supply management ICs are highly integrated solutions thatoffer essential functions, including power supply monitoring, supervision, margining and sequencing,and feature EEPROM for storing user configurations and fault logging.

RELATED PARTS
PART NUMBER

DESCRIPTIONCOMMENTS

LTM8053

40V, 3.5A Step-Down µModule Regulator

3.4V ≤ VIN ≤ 40V. 0.97V ≤ VOUT ≤ 15V. 6.25mm x 9mm x 3.32mm BGA Package.

LTM8032

36V, 2A Low EMI Step-Down µModule Regulator

3.6V ≤ VIN ≤ 36V, 0.8V ≤ VOUT ≤ 10V. EN55022B Compliant.

LTM8033

36V, 3A Low EMI Step-Down µModule Regulator

3.6V ≤ VIN ≤ 36V. 0.8V ≤ VOUT ≤ 24V. EN55022B Compliant.

LTM8026

36V, 5A CVCC Step-Down µModule Regulator

6V ≤ VIN ≤ 36V. 1.2V ≤ VOUT ≤ 24V. Constant Voltage Constant Current Operation.

LTM4613

36V, 8A Low EMI Step-Down µModule Regulator

5V ≤ VIN ≤ 36V. 3.3V ≤ VOUT ≤ 15V. EN55022B Compliant.

LTM8027

60V, 4A Step-Down µModule Regulator

4.5V ≤ VIN ≤ 60V, 2.5V ≤ VOUT ≤ 24V.

LTM8050

58V, 2A Step-Down µModule Regulator

3.6V ≤ VIN ≤ 58V, 0.8V ≤ VOUT ≤ 24V.

LTM8003

3.5A Version of LTM8002, 40V, 3.5A, IQ = 25µA
FMEA Compliant

3.4V ≤ VIN ≤ 40V, 0.97V ≤ VOUT ≤ 18V, 6.25mm × 9mm × 3.32 BGA Package.

LTM8065

40V, 2.5A Silent Switcher Step-Down µModule
Regulator

3.4V ≤ VIN ≤ 40V, 0.97V ≤ VOUT ≤ 18V, 6.25mm × 6.25mm × 2.32mm BGA Package.
Rev C

24

06/19

www.analog.com
For more information www.analog.com

 ANALOG DEVICES, INC. 2017-2019