COMPACT LOW POWER RF DRIVER
RF Driver for Acousto-Optic Modulators and Q-Switches
PRELIMINARY PRODUCT DATASHEETThis module (QCXXX-YYDC-ZZZ-AAV)
is a compact low power RF driver,designed to drive an acousto-optic(AO) modulator or Q-switch.
The unit has two digital modulation inputs: fixed andvariable. These controls allow the customer to issue
a pulse command of a “fixed” pulse width, theduration determined by the driver’s pulse width
control (settable by the customer), or issue a“variable” pulse command, the duration determinedby the input signal’s pulse width.
The output power is controlled by the analog input,
where the mode of operation is defined by ZZZ =A05 normal analog mode, or R05 analog switched tofull RF mode or a triggered RF Ramp Down mode
where ZZZ = FPS first pulse suppression mode or
PPK pre-pulse kill mode.
Other variations of these modes are also available.
The choices of frequency (XXX), output power (YY),and power control (ZZZ) option are “factory set”
when ordered. This driver has a zero crossing
function where the output pulse can besynchronized to the zero crossing point of the RF
Energy. When enabled the pulse to pulse stability isimproved.
This product conforms to the requirements of theEuropean Union Directive 2011/65/EU of theEuropean Parliament and of the Council on theRestriction of the Use of Certain Hazardous
Substances in Electrical and Electronic Equipment(RoHS).

Key Features• 24, 27.12, 40.68, 68, 80, or 110 MHz RF
frequency (XXX)• 0.01% quartz stabilized• Up to 24 W RF power output (YY)
• Two TTL digital modulation inputs: fixed andvariable pulse width• Up to 1 MHz pulse rate in Q-switch applications.
• Up to 10 MHz pulse rate in pulse pickingapplications• Analog modulation or triggered RF Ramp Down
Mode (ZZZ)• Synchronization to RF by ‘zero cross’
Key Benefits• Fault protection on low power, high power, andhigh VSWR
• Operates on 12, 15 or 24 VDC (AAV) (factory set)
Applications• Powering an AO Q-switch used to spoil the “Q”
of a CW laser in order to output an intense
pulse of light• Powering an AO modulator to pick pulses out ofan optical pulse train

QCXXX-YYDC-ZZZ-AAV................................................................................................................................................................................
Preliminary datasheet revision No. 2.1
As part of our policy of continuous product improvement, we reserve the right to change specifications at any time.

July 2016Page 1

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Technical Data
Supply voltage+12, +15 or +24 VDC (factory set)

Supply current≤3A

RF power output

2 to 24 W

Output impedance

50 

Output frequency

XXX = 024, 027, 041, 068, 080, or 110 as standard
where RF Frequency = 24.00, 27.12, 40.68, 68.00, 80.00
or 110.00 MHzFrequency stability± 0.01%

Extinction ratio≥ 50 dB

Harmonic distortion≤ -20 dB for units with output power ≤ 15 W
≤ -15 dB for units with output power > 15 W

Spurious levels
Analogue modulation input≤ -50 dBc
Impedance
Voltage range

1.5 k
0 to +5 VDC

The voltage range corresponds to 0 to 100% of the pre-adjusted maximum RF output power. For units configured with A05, R05 and M05

Digital modulation inputs

Impedance
Level

High impedance
TTL compatible (V_IL < 0.8V, V_IH > 2.0 V)

Mod in fixedStandard
Inverted digital input option (NEG)

Triggered on rising edge
Triggered on falling edge

Mod in variable

Standard
Inverted digital input option (NEG)

TTL V_IH = RF OFF
TTL V_IL = RF OFF

FPS/PPK input

Impedance
Level

High impedance
TTL compatible (V_IL < 0.8V, V_IH > 2.0 V)

TriggerStandard
Inverted digital input option (NEG)

Triggered on rising edge
Triggered on falling edge

For units configured with FPS,PPKDigital/analogue modulation
RF rise time/fall time
(10 to 90% RF power) 1≤ 35 ns

Zero crossing enable input

Impedance
Level

High impedance
TTL compatible (V_IL < 0.8V, V_IH > 2.0 V)

TriggerStandard
Active zero cross option (ZC) 2

TTL V_IH or no connection - disabled, TTL V_IL - enabled
TTL V_IH or no connection - enabled, TTL V_IL - disabled

Sync output

3.3 V signal, inverted in ZC units

Enable input< 3 W dissipation in standby mode

Normal operation
Standby mode
Driver reset

TTL V_IH or no connection
TTL V_IL
Momentary TTL V_IL

1

into 50 Ω load

2

ZC option enables zero cross by default

COMPACT LOW POWER RF DRIVER................................................................................................................................................................................
Preliminary datasheet revision No. 2.1
As part of our policy of continuous product improvement, we reserve the right to change specifications at any time.

July 2016
Page 2................................................................................................................................................................................

Output Indicators
STATUS INDICATOR LEDRed

Normal operationGreen

Standby mode

Yellow

Fault condition

Environmental Conditions
Operating temperature+10 to +55°C case temperature, non-condensing

Storage temperature-20 to +85°C, non-condensing

Connectors and Mechanical Data
RF output connector

SMA Female (recommended torque 0.45 Nm max 0.6 Nm).

Power and control connector

Molex 0430451221Mating connector

Molex 0430251200 with Molex 0430300008 crimp terminals

Cooling method

Contact cooled

Cooling spec

The driver must be attached to a heatsink capable of dissipating;
36W @ 12 V
45W @ 15 V
72W @ 24 V

Weight (driver only)

192 grams

Connector Pinout
POWER AND CONTROL CONNECTOR
12 positions header connector 0.118" (3.00mm)
Pin assignment
All input signals refer to ground (GND) unless otherwise stated. All outputs are open collector type 25 mA max current drain.
Pin 1

SYNC (out)Pin 2

FPS trigger (in)Pin 3

Mod in fixed (in)

Pin 4

GND

Pin 5

Mod in variable (in)Pin 6

Mod in analog (in)Pin 7Zero cross enable (in)Pin 8

Low power fault (out)Pin 9High power fault (out)Pin 10High VSWR load fault (out)Pin 11

Enable (in)Pin 12VDC

COMPACT LOW POWER RF DRIVER................................................................................................................................................................................
Preliminary datasheet revision No. 2.1
As part of our policy of continuous product improvement, we reserve the right to change specifications at any time.

July 2016Page 3

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Absolute Maximum Ratings
Important: Failure to remain within stated rating may cause instantaneous and irreparable damage to the driverSupply voltage+27 VDCRF power output

No DC feedback allowed

TTL/analog signal inputs-0.5 V to +5.5 V

Mod in fixed minimum pulse width

50 ns

Modulation repetition rates

Mod in fixed
Mod in variable

1 Hz to 1 MHz
DC to 10 MHz

RF power (W)Frequency (MHz)
24.00

27.12

40.68

68.00

80.00

110.001210

10101010

1015

24

24

24

20

20

1024

24

24

24

24

24

10

Supply voltage (V)Adjustments
RF Power Level Adjustment

Adjusts the output RF Power – clockwise increases power output

LP – Low Power Set Point

Adjusts the minimum power threshold.
The LP Fault output goes LOW if the output power is below this level 3

HP – High Power Set Point

Adjusts the maximum power threshold.
The HP Fault output goes LOW if the output power is greater than this level.

High VSWR Set Point (HVSWR)

Adjusts the module’s tolerance for a mismatched load connected to RF Out. If a mismatch isdetected, the HVSWR Fault output goes LOW, the status LED will change to YELLOW, andthe driver will cease output until reset by momentarily entering standby mode.

Pulse width (Mod in fixed)

Adjusts the length of time the driver outputs no RF energy after receiving a Fixed Input
trigger. 1 µs to 20 µs.

The following adjustments are used on units configured with FPS or PPK:FPS Start

Adjusts the initial power level of the first pulse.

FPS Slope

Adjusts how quickly the RF pulses return to their normal level after the FPS has been
triggered. 20 µs to 300 µs.

FPS Window

Adjusts the duration of the suppression pulse cycle. 20 µs to 300 µs.

3The LP Fault output will be suppressed whist modulating the RF power via analog modulation

Available First Pulse Suppression Modes
Modulation operating mode is “factory set” internally
FPS (First Pulse Suppression)

See figure 2

PPK (Pre Pulse Kill)

See figure 3

R05 (RF Switched to analog control)

See figure 4

A05 (Analog control)

See figure 5

M05 (Analog control configured for AOM)See figure 6

COMPACT LOW POWER RF DRIVER................................................................................................................................................................................
Preliminary datasheet revision No. 2.1
As part of our policy of continuous product improvement, we reserve the right to change specifications at any time.

July 2016Page 4................................................................................................................................................................................

LPHP

First Pulse Suppression (FPS) Operating Mode Control Diagram

SWR
ALARM

Figure 2+3.3V

External Fault Indicators

ENABLE

SUPPLYVOLTAGE+15V

ZERO CROSS

12111098754321B

A C

SYNC
OUT

TTL HIGH

Mod InA
FixedB

TTL LOWMod In TTL HIGH
Variable
TTL LOW

CFPS
Trigger

TTL HIGH

TTL LOW
3.3V HIGHSYNC OUTLOW

RF OutPulse Width
1-20μsFPS Window
20-300μs

Normal trigger polarity shown. Invert signals A, B, and C for NEG operation.

COMPACT LOW POWER RF DRIVER................................................................................................................................................................................
Preliminary datasheet revision No. 2.1
As part of our policy of continuous product improvement, we reserve the right to change specifications at any time.

July 2016
Page 5................................................................................................................................................................................
Figure 3

Pre Pulse Kill (PPK) Operating Mode Control Diagram

LPHP

SWR
ALARM

390XX-YYDMPPK-SC Driver Control+3.3V
ENABLE

SUPPLYVOLTAGE

External Fault Indicators+15V

ZERO CROSS

12111098754321B

SYNC
OUT

TTL
HIGH

Mod InA
FixedB

A C

TTL
LOW

Mod In TTL
HIGH
Variable
TTL
LOW

C

TTL
FPS
HIGH
Trigger TTL
LOW

SYNC
OUT3.3V HIGHLOW

RF OutPulse Width
1-20μsFPS Window
20-300μs

Normal trigger polarity shown. Invert signals A, B, and C for NEG operation.

COMPACT LOW POWER RF DRIVER................................................................................................................................................................................
Preliminary datasheet revision No. 2.1
As part of our policy of continuous product improvement, we reserve the right to change specifications at any time.

July 2016Page 6................................................................................................................................................................................

LP

HP

Analog Control (R05) Operating Mode Control Diagram

SWR
ALARM

Figure 4+3.3V

External Fault Indicators

ENABLE

SUPPLYVOLTAGE+15V

ZERO CROSS

12111096543C BA

Mod InFixedA871

SYNC
OUT

TTL HIGH

TTL LOWBCMod InVariable
Mod InAnalog

TTL HIGH

TTL LOW

5V

0V
3.3V

SYNC OUTLOW

RF OutPulse Width
1-20μsNormal trigger polarity shown. Invert signals A and B for NEG operation.

COMPACT LOW POWER RF DRIVER................................................................................................................................................................................
Preliminary datasheet revision No. 2.1
As part of our policy of continuous product improvement, we reserve the right to change specifications at any time.

July 2016
Page 7

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External Fault Indicators

LPHP

Analog Control (A05) Operating Mode Control Diagram

SWR
ALARMFigure 5+3.3V
ENABLE

SUPPLYVOLTAGEZERO CROSS+15V

12111096543871SYNC

C BA

Mod InFixedATTL HIGH

TTL LOWB

Mod InVariable

TTL HIGH

TTL LOW

5V

Mod InCAnalog
0V

3.3V

SYNC OUTLOW

RF OutPulse Width
1-20 μs

Normal trigger polarity shown. Invert signals A and B for NEG operation.

COMPACT LOW POWER RF DRIVER................................................................................................................................................................................
Preliminary datasheet revision No. 2.1
As part of our policy of continuous product improvement, we reserve the right to change specifications at any time.

July 2016
Page 8................................................................................................................................................................................
Figure 6Analog Control (M05) With AOM Compatible Output Operating Mode Control Diagram

Pulse Width
1-20 µs

Normal trigger polarity shown. Invert signals A and B for NEG operation.

COMPACT LOW POWER RF DRIVER................................................................................................................................................................................
Preliminary datasheet revision No. 2.1
As part of our policy of continuous product improvement, we reserve the right to change specifications at any time.

July 2016
Page 9................................................................................................................................................................................

Drawing

Dimensions in inches and [mm]

COMPACT LOW POWER RF DRIVER................................................................................................................................................................................
Preliminary datasheet revision No. 2.1

July 2016

As part of our policy of continuous product improvement, we reserve the right to change specifications at any time.

Page 10................................................................................................................................................................................
Order codes
Order codes are comprised of a standard device prefix followed by code letters or numbers which correspondto available options.
Example: QC027-20DC-A05-15V
A 27 MHz RF driver with two TTL digital modulation inputs (fixed and variable pulse width) and an analog input(A05) which enables control of the RF output power. Designed to drive an AO Q-switch requiring 20 W RF
power or less. Delivered as a RoHS compliant, contact cooled OEM module.

Order code①
XX②

QC①Characteristic
CodeX-Y③Y

D④DC

⑤-ZZ

⑥Z-

AA

⑦V

⑧--Frequency
024 = 24.00
MHz027 = 27.12
MHz041 = 40.68
MHz② Characteristic

080 = 80.00
MHz110 = 110.00
MHz

RF output powerCode

2 to 24 W Range (refer to table on page 4 for maximum power for chosen frequency)③ Characteristic

Digital modulation

Code

D = Standard

DN = Inverted digital④ Characteristic

Cooling

Code

C = Contact cooled (legacy denotation all QC drivers are contact cooled)⑤ Characteristic
Code068 = 68.00
MHzFirst Pulse Suppression ModeA05 = Analog
power control⑥ Characteristic
Code⑦ Characteristic
Code⑧ Characteristic
Code

R05 = Analog
power control(Switched)

FPS = First pulse
suppression

PPK = Pre pulsekill

M05 = Analogcontrol
configured for
AOM

Supply voltage (V)
12 V

15 V

24 V

Additional options (optional)
ZC = Active zero cross (enabled by default)
Custom unit identification (optional)
Usually customer specific denotation

For further information
E: sales@goochandhousego.com

goochandhousego.com

COMPACT LOW POWER RF DRIVER................................................................................................................................................................................
Preliminary datasheet revision No. 2.1

July 2016

As part of our policy of continuous product improvement, we reserve the right to change specifications at any time.

Page 11