Wavelength Electronics QCL500 User manual

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QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 1
QCL1500-00400-D
GENERAL DESCRIPTION:
The QCL1500 includes patented circuitry1ideal
for driving Quantum Cascade Lasers (QCLs)
where electronic noise, coupled through the
laser, can affect measurements.
This is an OEM controller, designed to be
integrated into field deployed systems or used
on a benchtop. It operates from dual DC power
supplies. Low noise can be achieved even with
certain switching power supplies.
An onboard Current Setpoint trimpot allows a DC
biastobeset. ItssignalsumswitharemoteAnalog
Input signal that can be negative or positive.
Safety: An onboard trimpot sets the current limit
as you monitor the setting - without driving current
through the QCL. Brownout, reverse voltage,
and overvoltage protection isolates the QCL from
power supply failures. An Overtemp Fault signal
minimizes the chance of failure due to overheated
electronics. An onboard Enable Switch controls
when current can flow to the QCL. A remote
Enable signal can also be used.
Applications: High performance chemical
sensing in biomedical, imaging, spectroscopy,
remote sensing, military, communications,
aerospace and materials processing industries.
To optimizenoise performance inyour application,
current range can be adjusted. Other product
variations are available. Please contact the
factory with your requirements at 406-587-4910
or [email protected].
1Covered by U.S. Patents 6,696,887; 6,867,644 and
7,176,755. Licensed from Battelle Memorial Institute.
Minimize spectral drift, center wavelength jitter,
and linewidth
FEATURES:
• Off the shelf models at 500 mA, 1A, 1.5 A
• Can be delivered in other current ranges up to 2A
- with noise minimized for your QCL
• Compliance voltage up to 16 V
• Low noise: < 1A RMS over 100 kHz bandwidth
(graphs on page 5)
• Analog Input Setpoint sums with onboard trimpot
• Safety: Current Limit, 1.25 second ON delay with
100 msec current ramp, Remote Enable signal,
brown out, reverse & over voltage, overtemp
protection circuits
• Remote Power On and Enable signals are TTL
compatible and fully isolated
• Adjustable Current Limit with monitor
• Local power & enable / disable switches
• Protection relay shorts output when current is
disabled
• Shielded from external interference
• Constant Current Mode operation
• 3 dB bandwidth 2 -3 MHz
• Status Outputs can drive LEDs
• Small Package 6.55 x 5.5 x 2.3”
• Compatible with P/N PTCxxK-CH precision
temperature controllers
• Accessories include cables and power supplies to
simplify integration.
November, 2010
Low Noise QCL Driver
Pb
RoHS
Com
p
liant
Ordering Information
QCL500
QCL1000
QCL1500
QCL2000
QCL-SMA-ADAPT
WCB310
WCB311
WCB312
PWRPAK-24V
NOISE SCAN
500 mA Low Noise QCL Driver
1 A Low Noise QCL Driver
1.5 A Low Noise QCL Driver
Product Variations are available up to 2 A
Convert signal pins to SMA connectors
Low Noise Cable: SMA to SMA
QCL 20 pin connector with cables
QCL Dual Power Supply wiring kit
24 VDC Switching Power Supply
Noise Characterization Scan
e

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QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 2
QCL1500-00400-D
Figure 1
Quick Connect
QUICK CONNECT
More details (and cautions) are available in the Pin Descriptions and Operating Sections of this
datasheet (pages 7 and 8 respectively).
Until you are comfortable with the driver operation, we recommend you use a test load instead
of an actual QCL. A resistor, metal film, TO-220, 50 W, is a typical test load. Two vendor
numbers are:
Caddock MP850-10.0-1% (Digikey part number MP850-10.0-F-ND) or
Ohmite TCH35P10R0JE (Digikey part number TCH35P10R0JE-ND)
10 :, 50 W
metal lm
resistor
QCL + *
Pin 19
QCL -
Pin 20
* Internally grounded
Figure 2
Example Test Load
NOTE: At 2 A, output current will be
compliance voltage limited with a
10 resistor. Use a 5 resistor such
as Caddock MP850-5.00-1% (Digikey
part number MP850-5.00-F-ND).
1 No Connect
2 No Connect
3 Remote Power On -
4 Remote Power On +
5 Remote Enable - *
6 Remote Enable +
7 QCL Enable Status
8 Power Status
9 Overtemp Fault Status
10 Current Monitor
11 Limit Monitor
12 Monitor Ground
13 ANALOG IN
14 ANALOG IN GND
15 Ground
16 V+
17 V -
18 POWER GROUND
19 QCL + (Ground)
20 QCL -
INTERNALLY
TIED
QCL
+
-
0-5 V
Can go negative by the
DC offset of onboard
setpoint trimpot.
+
-
ENABLED = HI
DISABLED = LO
ON = HI
OFF = LO
V
V
TTL
TTL * *
Optically isolated from ground
(user-configurable)

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QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 3
QCL1500-00400-D
Positive Supply Voltage
Negative Supply Voltage
Output Current (See SOA Chart [1])
Internal Power Dissipation, +25˚C, no air
Operating Temperature, case [2]
Storage Temperature
Weight
Size
ELECTRICAL AND OPERATING SPECIFICATIONS
Volts DC
Volts DC
mA
Watts (model dependent)
˚C
˚C
lbs
inches
(mm)
UNITVALUE
5
5
5
0.75
+ 22
- 22
+ 25
- 25
500, 1000, 1500
10, 16 , 21
- 40 to + 50
- 55 to +125
2
5.5 x 6.55 x 2.3
(140 x 166 x 59)
V+
V-
IOUT
PMAX
TOPR
TSTG
ABSOLUTE MAXIMUM RATINGS
RATING SYMBOL
ppm
ppm
ppm
Volts
nsec
nsec
V / sec
MHz
sec
msec
%
mA
A RMS
nA / SHz
V DC
V DC
mA
mA
mA
15
15
15
3
3
+ 25
- 25
10
10
10
16
250
200
30
2
1.25
100
90
2
1
2
+ 24
- 24
250
100
450
CONSTANT CURRENT CONTROL
Short Term Stability, 1 hour
Long Term Stability, 24 hours
Temperature Coefficient
Compliance Voltage, Laser Load [3]
Rise Time
Fall Time
Slew Rate
Bandwidth, 3 dB
Delayed start
Slow Start ramp
Depth of Modulation [4]
Leakage Current
NOISE (graphs on page 5) [5]
Noise Current (RMS) [1 A model]
Noise Current Density
POWER SUPPLY
Voltage, V +
Voltage, V-
Current, V+ supply, quiescent
Current, V - supply, quiescent
Inrush current requirement [6]
TYPMIN MAX UNITSTEST CONDITIONSPARAMETER
TAMBIENT = 25˚C
TAMBIENT = 25˚C
- 24 V in
to full scale
to full scale
large signal (< 90% full scale)
to full scale
at 500 kHz
IOUT= 100mA, 100 kHz bandwidth
IOUT= 100mA, RLOAD= 10 
[1] SOA: Safe Operating Area - Determine if power dissipated in the QCL Driver with your operating parameters
exceeds limits. Online calculator at http://www.teamwavelength.com/support/calculator/soa/soald.php .
Charts are also available in Appendix A.
[2] Derating begins at 35°C. QCL2000 maximum operating temperature is 35°C. Derating starts at 25°C.
[3] Safety circuits monitor tightly around the nominal 24 V inputs. For a lower input voltage (more efficient for QCLs
with lower compliance voltages), contact the factory for a Product Variation.
[4] As frequency increases on the analog input, the
peak-to-peak output amplitude diminishes. For example,
these graphs show the waveform shape at 10 Hz and
500 kHz. Depth of modulation continues to decrease
after 500 kHz.
[5] How noise measurements are made is detailed in WEI’s Low Noise Measurement Protocol Technical Note.
[6] Negative power supply must source at least 450 mA. If current to QCL exceeds 450 mA, DC power supply
capacity should be QCL current plus quiescent current
0 mA
Full Current
100% Depth of Modulation at 10 Hz
100 %
0 %
90% Depth of Modulation at 500 kHz
90 %
95 %
5 %

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QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 4
QCL1500-00400-D
ELECTRICAL AND OPERATING SPECIFICATIONS, continued
0
0
0
0
0
V
k
A / V
A / V
A / V
V
V
V
MHz
ppm
%
V
%
A / V
A / V
A / V
A / V
A / V
A / V
sec
5
12
12
2.5
1
5.75
4
1
0.1
0.2
0.3
1.8
25
0.5
1
0.2
0.09
0.4
0.19
0.6
0.28
10
INPUT
Analog In
Analog In Input Impedance
Analog In Damage Threshold
Analog In Transfer Function
Analog In Transfer Function
Analog In Transfer Function
Remote Enable / Disable & Remote Power On
Status Outputs
MONITOR
Current Monitor Range
Current Monitor Bandwidth, 3 dB
Current Monitor stability
Accuracy Current Monitor to Actual
Limit Monitor Range
Accuracy Limit Monitor to Actual
MONITOR TRANSFER FUNCTION
Current Monitor
Limit Monitor
Current Monitor
Limit Monitor
Current Monitor
Limit Monitor
THERMAL
Pin Solderability
TYPMIN MAX UNITSTEST CONDITIONSPARAMETER
Sum of (trimpot + AI) < 0 V or > 5.5 V
QCL500
QCL1000
QCL1500
TTL compatible (source min of 5 mA)
TTL compatible (can source 25 mA)
above 10% full scale
Limit is > 20% of setpoint
QCL500
QCL500
QCL1000
QCL1000
QCL1500
QCL1500
Solder temp @ 260˚C

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QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 5
QCL1500-00400-D
ELECTRICAL AND OPERATING SPECIFICATIONS, continued
Model
QCL500
QCL1000
QCL1500
RMS noise A
(100 kHz BW)
0.4
0.7
1.0
Average Current Noise
Density - nA / SHz
1.0
2.0
3.0
How noise measurements are made is detailed in
WEI’s Low Noise Measurement Protocol Technical
Note.
Figure 3
Typical Current Noise Density and Cumulative Noise Current (RMS)
Measured with short cables, on unshielded benchtop, 10 load, chassis grounded

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QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 6
QCL1500-00400-D
ELECTRICAL AND OPERATING SPECIFICATIONS, continued
There is a slight (2%) overshoot
when the driver is operating in
current limit (with the limit value
set well below the setpoint). We
recommend that you operate with
the limit above the setpoint.
Figure 4
Typical Square Wave Response
Figure 5
Typical Limit Circuit Response, Limit set well below setpoint
10 kHz 600 kHz
Limit
Limit

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QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 7
QCL1500-00400-D
Reserved
Not used
Return for Remote Power On signal - optically isolated
OFF = LO (< 0.3 V). ON = HI (> 3 V).
Toggle to reset a protection circuit error.
Return for Remote Enable signal - optically isolated
Disable = LO (<0.3 V). Enable = HI (>3 V).
Toggle to reset a protection circuit error.
HI = Current Enabled. LED drive compatible. Source up to 25 mA, 12 V.
HI = Power ON. LED drive compatible. Source up to 25 mA, 12 V.
HI = FAULT triggered. Indicates internal parts are over acceptable
temperature. LED drive compatible. Source up to 25 mA, 12 V.
Monitor Output Current level. 0 to 2.5 V. Transfer functions vary with model.
Monitor Current Limit Setpoint. Output 0 to 5 V. Transfer functions vary with
model.
Monitor Ground - use with Status or Monitors. Not designed for high current
return.
Analog voltage sums with onboard setpoint trimpot - can be positive or
negative (Do not drive negative below the DC level set by onboard setpoint
trimpot or above 5.5 V) Setpoint range 0 to 5 V. Input impedance is 1 k.
Ground for Analog Input Voltage. Not designed for high current return.
Ground - can be used to ground chassis.
Positive DC power to the unit, typically +24 V
Negative DC power to the unit, typically -24 V
GROUND - designed for high current return to the power supplies.
Ground - Source current to QCL (see diagram below)
Sink current from QCL (see diagram below)
No connect
No connect
Remote Power On -
Remote Power On +
Remote Enable -
Remote Enable +
QCL Enable Status
Power Status
Overtemp Fault Status
Current Monitor
Limit Monitor
Monitor Ground
ANALOG IN
ANALOG IN GND
Ground
V+
V -
POWER GROUND
QCL + (Ground)
QCL -
FUNCTIONPIN DESCRIPTIONPIN NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
PIN DESCRIPTIONS (left to right)
QC
Laser
-V
QCL +
QCL -
QCLxxx
Current Sink
Sink current from QCL (see diagram below)
Ground - Source current to QCL (see diagram below)
Ground
Analog voltage sums with onboard setpoint trimpot - can be positive or
negative (Do not drive negative below the DC level set by onboard setpoint
trimpot or above 5.5 V) Setpoint range 0 to 5 V. Input impedance is 1 k.
Ground for Analog Input Voltage. Not designed for high current return.
QCL -
QCL + (Ground)
Ground
ANALOG IN
ANALOG IN GND
FUNCTIONPIN DESCRIPTIONPIN NO.
1
2
3
4
5
Front Panel Connector (left to right)
Figure 6
QCL wiring polarity and grounding

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QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 8
QCL1500-00400-D
OPERATING PROCEDURES
1. Thermal Design
Verify that the Internal Heat Dissipation for your application does not exceed the maximum allowed.
The Safe Operating Area chart details the location of this limit.
Online, at http://www.teamwavelength.com/support/calculator/soa/soald.php, choose the model
of QCL driver you will be using. Enter your power supply and QCL characteristics to determine internal
power dissipation with your design. Alternately, you can use the SOA charts in Appendix A and
manually draw your system load line. Airflow is required in some cases.
Note that the FAULT LED will light and the output current will be disabled if the internal temperature of
the driver exceeds safety limits.

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QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 9
QCL1500-00400-D
OPERATING PROCEDURES, continued
2. Configure control for Local Only, Local & Isolated Remote, or Local &
Grounded Remote. Wire Remote Signals.
The Remote Power On and Remote Enable signals interact with the onboard switches. A DIP switch
on the bottom of the board configures the interaction. Factory default is Local Only.
To access the DIP switch, remove the seven screws attaching the baseplate to the shield. Use
the mounting tabs to lever the baseplate off the shield. The fit is deliberately tight. Note that the
components are Electro-static Discharge (ESD) sensitive. Make these changes in an ESD safe zone.
Remove 7 screws
The switch location is given in Figure 10:
If you will be using the REMOTE inputs, wire them now. TTL compatible, up to 12 V.
Pin 3 Remote Power On -, Pin 4 Remote Power On +
Pin 5 Remote Enable -, Pin 6 Remote Enable +
STATE
Local Only
All switches to right or ON
FACTORY DEFAULT
Local Plus Isolated Remote
All switches to left or OFF
Local Plus Grounded Remote
Swith 1 & 3 OFF
Switch 2 & 4 ON
SWITCH POSITION INTERACTION
Remote inputs are ignored. Local Switches only.
If either Remote Signal or Local Switch is OFF or
disabled, Power is OFF or Current is DISABLED.
Remote signal is optically isolated. Wire to
Remote Power ON - & + and Remote Enable - & +.
If either Remote Signal or Local Switch is OFF or
disables, Power is OFF or Current is DISABLED.
Remote signal negative is tied to ground. Wire to
Remote Power + and Remote Enable +.
1
2
3
4
ONOFF
1
2
3
4
ONOFF
1
2
3
4
ONOFF
Figure 9
Access to switches
Figure 10
Switch location
If you prefer a different default
from the factory, please contact
us at 406-587-4910 or
[email protected]
[email protected]

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QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 10
QCL1500-00400-D
AC(L) AC(N)FG-V+V AC(L) AC(N)FG-V+V
16 18 17
V+
POWER
GROUND
V-
**R=150k:
On 20 pin connector
POSITIVE SUPPLY NEGATIVE SUPPLY
OPERATING PROCEDURES, continued
** If ground is somewhere tied to earth ground (e.g. at a DAQ card), tie common point to
ground through high resistance to avoid triggering safety circuits.
• AC: In to both power supplies
• AC Safety ground #1: Connect two FG terminals
• AC Safety ground #2: Connect FG to AC chassis ground
• Common Ground: Connect between -V of positive supply and +V of negative supply
• Attach to the QCL driver - V+, POWER GROUND, V -
4. Attach dual power supplies
For safety, it is important that your power supply integrate an effective current limit circuit. Ground
loops can be avoided by choosing a power supply with the chassis not tied to ground. WEI offers
switching power supplies (PWRPAK-24V), a 20 pin cable (WCB311), and a power supply kit (WCB312)
to simplify setup. Twist wire pairs to minimize noise. See TDK/Lambda instruction manual for
mounting and other design considerations. Here is an example schematic and wiring diagram for
power supply setup:
Figure 8
Example power supply wiring
3. Wire Test Load
To become familiar with the QCL driver operation, we recommend that you wire a test load first. This
can be as simple as a resistor. We recommend a metal film, TO-220, 50 W, as a typical test load. Two
vendor numbers are: Caddock MP850-10.0-1% (Digikey part number MP850-10.0-F-ND) or Ohmite
TCH35P10R0JE (Digikey part number TCH35P10R0JE-ND)
The QCL driver is not designed to operate with the QCL pins shorted. Safe Operating Area thermal
limits will be exceeded. The following schematic shows an example test load and wiring.
10 :, 50 W
metal lm
resistor
QCL + *
Pin 19
QCL -
Pin 20
* Internally grounded
Figure 7
Example test load

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QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 11
QCL1500-00400-D
5. Setup Monitors
Attach a DVM or other voltage monitoring device to the Current Monitor (Pin 10) and Limit Monitor
(Pin 11). Reference to Monitor Ground (Pin 12). Transfer functions are:
Examples:
QCL500 - 2.5 V on the Current Monitor pin, equivalent current is (2.5 V * 0.2 A / V) or 500 mA.
QCL1000 - 1.8 V on the Current Monitor pin, equivalent current is (1.8 V * 0.4 A / V) or 0.72 A.
QCL1500 - 2.0 V on the Current Monitor pin, equivalent current is (2.0 V * 0.6 A / V) or 1.2 A.
QCL500 - 5 V on the Limit Monitor pin, equivalent limit current is (5 V * 0.09 A / V) or 450 mA.
QCL1000 - 2.5 V on the Limit Monitor pin, equivalent limit current is (2.5 V * 0.19 A / V) or 470 mA.
QCL1500 - 3.2 V on the Limit Monitor pin, equivalent limit current is (3.25 V * 0.28 A / V) or 910 mA.
6. Power up the unit
Turn on power to the DC supplies. Flip the POWER ON switch to ON. The POWER ON LED lights. If
the LED does not power on, review REMOTE vs. LOCAL switch settings (Step 4) and the state of the
REMOTE POWER ON signal (Pin 4 referenced to Pin 3).
7. Set Current Limit & Zero Output Current
Choose Current Limit current to be above the normal setpoint, but below the damage threshold of
the QCL. Monitor the Current Limit (between Pin 11 & 12). Rotate the Current Limit Setpoint trimpot
clockwise to increase the limit current setting. Example conversions:
QCL500 - Want 425 mA Limit, equivalent voltage is (0.425 A / 0.09 A / V) or 4.7 V.
QCL1000 - Want 750 mA Limit, equivalent voltage is (0.750 A / 0.19 A / V) or 3.9 V.
QCL1500 - Want 1.5 A Limit, equivalent voltage is (1.5 A / * 0.28 A / V) or 5.3 V.
Rotate the SET trimpot on the front panel completely counter clockwise to zero the output current
setpoint.
OPERATING PROCEDURES, continued
Model
QCL500
QCL1000
QCL1500
Limit MON
0.09 A / V
0.19 A / V
0.28 A / V
Current MON
0.2 A / V
0.4 A / V
0.6 A / V
• Power On: Switch and indicator
• Enable Current: Switch and indicator
• Over Temperature Fault indicator
• Current Setpoint trimpot
• Current Limit Setpoint trimpot
QCL1500
01A105409201
Covered by U.S.
Patents 6,696,887;
6,867,644 and
7,176,755

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QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 12
QCL1500-00400-D
8. Enable Output Current & Set Current Setpoint
Flip the ENABLE switch to ON. The ENABLE LED lights. If the LED does not power on, review
REMOTE vs. LOCAL switch settings (Step 4) and the state of the REMOTE ENABLE signal (Pin
6 referenced to Pin 5). Rotate the SET trimpot clockwise to increase the current setpoint. Current
monitor should now show voltage equivalent to output current.
EXAMPLES:
QCL500 - Want 400 mA Output Current, equivalent voltage is (0.400 A / 0.2 A / V) or 2 V.
QCL1000 - Want 950 mA Output Current, equivalent voltage is (0.950 A / 0.4 A / V) or 2.375 V.
QCL1500 - Want 1.25 A Output Current, equivalent voltage is (1.25 A / 0.6 A / V) or 2.08 V.
Note, wait at least one second between turning POWER ON and enabling current. Allow one hour for
best performance.
9. Disable Output Current and Power Down the unit
Flip the ENABLE switch to the OFF position (or send a LO voltage to REMOTE ENABLE). The
ENABLE LED goes out. After a 9.5 msec delay, the current turn off ramp is 5.5 sec.
Flip the POWER switch to the OFF position. The POWER LED goes out. Turn off the power to the
dual DC power supplies.
10. Remove test load and wire in a Quantum Cascade Laser
Wire the QCL for proper current direction. Note that pin 19 (QCL +) is also internally attached to
ground.
11. Recovery from a Protection Circuit trip or FAULT error
If the voltage from the dual power supplies to the QCL driver is over or under voltage limits, the
protection circuits will trip and latch off. Output Current is disabled. To restart after correcting the
cause of the error, disable the current (using switch or remote ENABLE signal) then toggle the Power
OFF then ON (signal or switch). Wait 1 second to re-enable current.
If voltage to the QCL driver is reversed, protection diodes go into conduction. The rail is held one
diode drop from ground. This condition will continue until power from the power supply is removed
or the fuse for that rail blows. To restart after correcting the cause of the error, disable the current
(using switch or remote ENABLE signal) then toggle the Power OFF then ON (signal or switch). Wait 1
second to re-enable current.
OPERATING PROCEDURES, continued
QC
Laser
-V
QCL +
QCL -
QCLxxx
Current Sink
Figure 11
QCL wiring polarity and grounding

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QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 13
QCL1500-00400-D
APPLICATION NOTES
OPTIMIZE NOISE
Noise is specific to each application. Here are a few suggestions for reducing system noise:
• Buy the right controller for your QCL. The lower the maximum current capacity, the lower the
current noise. Contact the factory for a custom range.
• Manage ground loops. Any current flowing through inadvertant ground loops will show as current
noise. See “Ground Loop Avoidance” Application Note.
• Keep the ANALOG IN signal clean. Any noise on that input will transfer directly to the output
current.
• If possible, tie the QCL driver chassis to ground (without introducing ground loops). This reduces
60 (or 50) Hz peaks. Pin 15 on the 20 pin connector is ground. It can be wired to a screw on the
chassis, to the mounting slots, etc. Note that despite the peak at 60 Hz, 0 ot 100 kHz RMS noise
for the two graphs is equivalent.
Figure 12: 60 Hz noise with chassis floating and chassis grounded
• Choose the right power supply. Wavelength has tested with a switching TDK / Lambda power
supply (PWRPAK-24V) as well as linear supplies. The better the switching supply, the better the
noise performance. Specifications to look at are minimum noise and maximum load rejection.
Figure 13: Example linear and switching power supply noise current density graphs.
Linear Switching
• Filter the power supply. Use an off-the-shelf EMI filter such as TDK / Lambda’s MAW series.
• Fan wiring. Do not power a fan from the dual supplies. Keep it on a completely different power
supply.
• Minimize lead length to the power supply and load. Use twisted pair, shielded cables, or SMAs.

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QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 14
QCL1500-00400-D
APPLICATION NOTES
USE SMA cables for QCL and / or ANALOG IN
QCL1500
01A105409201
Covered by U.S.
Patents 6,696,887;
6,867,644 and
7,176,755
If you will not be mounting the QCL driver on a
PCB, you can use Molex high pressure housing
7880 family.
(6 pins shown)
20 pin Molex part number: 10-11-2203.
5 pin Molex part number: 10-11-2053
Crimp Molex part number: 08-50-0005.
WCB311 is a 20 pin connector with cables.
CABLE ADAPTER IMPROVE BANDWIDTH
USE STATUS PINS TO DRIVE LEDs
typical red
or green
LED
STATUS
PIN
Ground
Pin 12
10 k :
The STATUS pins output 12 V, up to 25 mA.
With this typical hookup, we assume 1.5 V
forward voltage across LED and 1 mA drive
current.
12 V - 1.5 V ~ 1 mA
10 k
Minimize cable length to improve bandwidth.
Sometimes twisting wires for signal pairs will
also improve bandwidth.
SET LIMIT MORE PRECISELY
The actual limit will be lower than the equations
indicate. If you want a more exact setting, set
the setpoint above the limit and monitor actual
current instead of current limit as you adjust the
limit current trimpot.
If SMA low noise cables are better for your application,
order the QCL-SMA-ADAPT. The pins on the front
panel are converted to SMA connectors
Pinout is (left to right)
QCL - : Center Pin
QCL + : Shield
ANALOG IN: Center Pin
ANALOG IN GROUND: Shield
WCB310 is an SMA cable, male to male, 36” long

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QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 15
QCL1500-00400-D
AC(L) AC(N)FG-V+V AC(L) AC(N)FG-V+V
16 18 17
V+
POWER
GROUND
V-
On 20 pin connector
POSITIVE SUPPLY NEGATIVE SUPPLY
WCB311 20 PIN CONNECTOR WIRING DIAGRAM
WCB312 POWER SUPPLY KIT
FUSE REPLACEMENT
APPLICATION NOTES
Remove the baseplate to access the fuses. Two 5 A, 5 x 20 mm, SLO-BLOW fuses can be replaced.
There are no other user serviceable parts inside the QCL driver. Change fuses in an ESD safe zone.
No connect
No connect
Remote Power On -
Remote Power On +:
Remote Enable -
Remote Enable +
QCL Enable Status
Power Status
Overtemp Fault Status
Current Monitor
Limit Monitor
Monitor Ground
ANALOG IN
ANALOG IN GND
Ground
V+
V-
POWER GROUND
QCL + (Ground)
QCL -
WIRE COLORPIN DESCRIPTIONPIN NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
CABLE
4 cond
4 cond
4 cond
4 cond
6 cond
6 cond
6 cond
6 cond
6 cond
6 cond
2 cond
2 cond
1 cond
3 cond
3 cond
3 cond
2 cond
2 cond
BLK
WHT
GRN
RED
BLU
GRN
ORG
WHT
RED
BLK
RED
BLK
BLK
RED
WHT
BLK
BLK
RED
This kit is available to simplify wiring of the PWRPAK-24V. It includes:
• AC: 2 twisted pair black & white 14 ga 24” wires (blk is intended for line, white for neutral)
• Qty 6 - 14 ga ring terminals to attach the AC wires to the PWRPAK-24V screw terminals
• AC Safety ground #1: 22 ga green wire, 10” with ring terminals on both ends - connect two FG
terminals
• AC Safety ground #2: 22 ga green wire, 10” with one ring terminal - connect FG to AC chassis
ground
• Common Ground: 24 ga black wire, 10” with ring terminals on both ends - connect between -V of
positive supply and +V of negative supply
• Qty 3 - 24 ga ring terminals to attach to the
wires from the 3-pin power cable
(V+, POWER GROUND, V -)
Pin 1 is indicated on the molded plastic connector, or by the lack of wires in Pins 1 & 2. The latching
bar is on the side nearest the baseplate.
CABLE LENGTH
36”
36”
12”
36”
24”
24”

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© 2010
QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 16
QCL1500-00400-D
MECHANICAL SPECIFICATIONS
2.32
6.00
.28
6.55
4.00 .50
5.00
5.50
.75
R
.141
.281
.233
TYP
.59
.062
Dimensions are in inches [mm]. Tolerance is ± 5%.
[166]
[152]
[12.7]
[102]
[127]
[5.8]
[140]
[7.1]
[3.6]
[7.1]
[59]
[1.57]

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© 2010
QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 17
QCL1500-00400-D
PCB MOUNTING GUIDELINES
The QCL driver needs to be mounted by the baseplate mounting holes, not supported by the solder
joints. The solder joints are not meant for mechanical support.
To use #8 screws instead of 1/4-20s for mounting, a shoulder washer such as 12SWS1030 from
Micro Plastics, Inc. can be used.
4.000.75 5.50
6.000
.28
6.55
.281
4 PLS
.673
2.312
.100
.849
6.550
5.550
1.900
20 PLS
.038

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© 2010
QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 18
QCL1500-00400-D
(5) 67±0.5
(5.5) 17
(10) 62±0.5 8
80±1
868±0.5
19MAX
(14)
(17) 8.4
A : MODEL NAME, INPUT VOLTAGE RANGE, NOMINAL
OUTPUT VOLTAGE, MAXIMUM OUTPUT CURRENT AND COUNTRY OF MANUFACTURE ARE SHOWN HERE IN
ACCORDANCE WITH THE SPECIFICATIONS.
B : M3 EMBOSSED, TAPPED AND COUNTERSUNK HOLES (2)
FOR CUSTOMER CHASSIS MOUNTING. SCREWS MUST NOT PROTRUDE INTO POWER SUPPLY BY MORE THAN 6m/m.
SEE NOTE C
NOTES NAME PLATE
7.3
(10.1) VOLTAGE ADJUSTMENT
5-M3.5
SEE NOTE B
LED
82±1
8
15
MORE THAN 6m/m. SCREWS MUST NOT PROTRUDE INTO POWER SUPPLY BY
C : M3 TAPPED HOLES (2) FOR CUSTOMER CHASSIS MOUNTING.
AC(L) AC(N) FG -V +V
NAME PLATE
31.5±1
INPUT : 100-240VAC 0.5 A
OUTPUT : 5 V 3 A
MADE IN JAPAN
BARCODE
50 / 60Hz
HWS15 - 5 /A
HWS15 - 5 /A
INPUT : 100-240VA 0.5A 50/60Hz
OUTPUT : 5 V 3 A
SEE NOTE A
(67.5)
4
45JB
IND.CONT.EQ.
A224-02-01/A-A
(unit : mm)
MODEL
HWS15/A
NLFG-V+V
INPUT : 100-240VA 0.5A 50/60Hz
HWS15 - 5 /A
OUTPUT : 5 V 3 A
4
MECHANICAL SPECIFICATIONS PWRPAK-24V
Diagram courtesy TDK-Lambda - data subject to change
Additional use and mounting guidelines are available in
the PWRPAK-24V datasheet.

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QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 19
QCL1500-00400-D
APPENDIX A
SAFE OPERATING AREA & AIRFLOW REQUIREMENTS
Caution:
Do not exceed the Safe OperatingArea (SOA). Exceeding the SOA voids the warranty.
An online tool is available for calculating Safe Operating Area at:
http://www.teamwavelength.com/support/calculator/soa/soald.php.
To determine if the operating parameters fall within the SOA of the QCL driver, the maximum voltage drop across the
driver and the maximum current must be plotted on the SOAcurves.
These values are used for the example SOAdetermination:
Device: QCL1500
V- = 24 Volts
V
QCL = 10 Volts
I
QCL = 1.25Amp
Follow these steps:
1. Determine the maximum voltage drop across the driver, V- - VQCL, and mark on the X axis.
Example: 24 V - 10 volts = 14 volts, PointA
2. Determine the maximum current, IQCL, through the driver and mark on the Y axis:
(1.25Amp, Point B)
3. Draw a horizontal line through Point B across the chart. (Line BB)
4. Draw a vertical line from PointA to the maximum current line indicated by Line BB.
5. Mark total supply voltage V- on the X axis. (Point C - 24 V)
6. Draw the Load Line from where the vertical line from pointA intersects Line BB down to Point C.
Refer to the chart shown below and note that the Load Line is within the Safe Operating Area for this device, but
requires airflow (34 cfm) to maintain safe operation.

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QCL500, QCL1000, QCL1500 Low Noise Quantum Cascade Laser Drivers
PAGE 20
QCL1500-00400-D
SAFE OPERATING AREA & AIRFLOW REQUIREMENTS
The charts on this page can be used to determine if your design falls within the
Safe Operating Area (SOA) for the QCL series driver that you are using. For an
example of how to use these charts, reference the previous page. There is also an
online Safe Operating Area calculator available at:
http://www.teamwavelength.com/support/calculator/soa/soald.php.