Wavelength Electronics QCL OEM Series User manual
Applies to Product Revisions A – D
© March 2019
ORDERING INFORMATION
PART NO DESCRIPTION
QCL500 OEM 500 mA Low Noise QCL Driver
QCL1000 OEM 1.0 A Low Noise QCL Driver
QCL1500 OEM 1.5 A Low Noise QCL Driver
QCL2000 OEM 2.0 A Low Noise QCL Driver
QCL OEM(+) Series Positive polarity OEM models
PWRPAK-24V 24 VDC switching power supply
(2x required)
WCB312 Dual power supply wiring kit
NOISESCAN Noise characterization scan
55-110014 SMA-BNC low noise cable
WCB310 SMA-SMA low noise cable
QCLTL Series Test load kits for the QCL OEM
LOWEST-NOISE DRIVER AVAILABLE
The QCL OEM Series drivers use patented1circuitry to
produce the lowest current noise density of any commercially
available QCL driver. The 500 mA QCL driver exhibits noise
ULTRA-NARROW QCL LINEWIDTH
In order to maintain their characteristically tight center
be powered by drivers with exceptionally low current noise
density. Our customers have reported achieving narrower
linewidths with these drivers than any other they’ve used.
Battelle Memorial Institute.
APPLICATIONS
The QCL Series drivers are used in trace element detection
This driver is well suited to applications requiring fast
measurement times and ultra high sensitivity.
REVERSE POLARITY AVAILABLE
lead is attached to the case and it is desirable to ground
also available in the OEM package. See QCL OEM(+).
PROTECT YOUR QCL INVESTMENT
All the essential control and monitor functions you expect in
along with protection circuitry to safeguard your QCL from
and electrical faults.
FEATURES AND BENEFITS
•
• Can be delivered in other current ranges up to 2 A
•
• Safety features protect your QCL investment
»Adjustable soft-clamping current limit
»
protection
»Driver over-temperature protection circuit
»Relay shorts output when current is disabled
• Local and Remote Power-On and Enable control
• Analog modulation input between -5V and +5V
CONTENTS
QUICK CONNECT GUIDE 2
PIN DESCRIPTIONS 3
ELECTRICAL SPECIFICATIONS 5
SAFETY INFORMATION 7
OPERATING INSTRUCTIONS 8
TROUBLESHOOTING 13
TECHNICAL SUPPORT INFORMATION 14
MECHANICAL SPECIFICATIONS 22
CERTIFICATION AND WARRANTY 23
PAGE
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QCL OEM Series
Low-Noise Quantum Cascade Laser Driver
DATASHEET AND OPERATING GUIDE
© 2019 www.teamWavelength.com 2
QCL OEM SERIES LOW-NOISE DRIVER
QUICK CONNECT GUIDE
!
Visit the Wavelength Electronics website for the most
Figure 1 shows the front panel of the QCL OEM driver and
01D105409201
E
T
QCL
QCL1500
POWERENABL
ON ON
FAUL
SET
LIMIT
Covered by U.S.
Patents 6,696,887,
6,867,644 and
7,176,755.
ANALOG
Figure 1. QCL Driver Front Panel
Figure 2 shows the wiring diagram for the QCL driver and
external electronics. If you are using the Remote Power
page 11 for
load in place of the laser (Figure 3). Recommended test
LOAD
• Wavelength part number QCL TEST LOAD (available
for < 1 A and 1.5 A current ranges)
•
•
RLOAD
• Wavelength part number QCL TEST LOAD (available
•
TTL Optional Remote Enable
HI = Enabled; Low = Disabled
Optional Analog Setpoint
(-5 V to +5 V)
+
-
TTL Optional Remote Power On
HI = On; Low = Disabled
DVM
Reserved
Remote Power On –
Remote Power On +
Remote Enable –
Remote Enable +
Output Enable Status
Power Status
Overtemp Fault Status
Current Setpoint Monitor
Current Output Monitor
Limit Monitor
Monitor Ground
Analog Input
Analog Input Gnd
V+
V–
PGND
QCL+ (Ground)
QCL–
GND
+5V AUX
ANALOG
SMA QCL
SMA
QCL
+
+
_
_
POWER ENABLE
22
NOTES
1. The Remote Power On − and
Remote Enable − inputs can be
optically isolated from ground.
2. The SMA connectors are electrically
isolated from the QCL chassis.
3. The 150 kΩ resistor is required in
some circumstances. Refer to the
section on wiring the power supplies.
1
1
V+ V−
14
13
12
11
10
9
8
7
6
5
4
3
2
1
3
2
1
4
3
2
1
150 kΩ
Earth
Ground
3
J5
J4
J1
Figure 2. QCL Wiring Diagram, Revision D
R
LOAD
Pin J5-3, or
QCL SMA Center Pin
Pin J5-4, or
QCL SMA Shield
Figure 3. Test Load
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QCL OEM SERIES LOW-NOISE DRIVER
PIN DESCRIPTIONS
Table 1. Pin Descriptions, WCB31X Cable Descriptions
PIN NAME SYMBOL COLOR PIN DESCRIPTION
Connector J1, WCB311 14-Pin Input/Output Cable
1 Analog In GND Red Ground for analog setpoint input. Pin is not rated for high current return.
2 Analog In Black
Analog setpoint input. The voltage input on this pin sums with the onboard
refer to Table 3. Damage threshold is ±10V.
3 Monitor Ground Black
This pin is not rated for high current.
4Current Limit
Monitor LIM_MON Red Table 3.
Range 0 to 5 V.
5Current Output
Monitor1OUT_MON Brown
Table 3.
Range 0 to 5 V on Revision D models. Refer to note 1 for range of previous
instrument revisions.
6Current Setpoint
Monitor SET_MON White
Table 3. Range 0 to 5 V.
Overtemp Fault
Status Orange
Power Status Green
9Output Enable
Status Blue
25 mA at 12 V.
10 Remote Enable + Red
11 Remote Enable – Green Return for Remote Enable signal. Can be optically isolated from the
page 11.
12 Remote Power On + White
13 Remote Power On – Black Return for Remote Power On signal. Can be optically isolated from the
page 11.
14 Reserved –
Connector J4, WCB313 3-Pin QCL Power Cable
1 PGND Black
2 V– White Negative DC power supply input. Typically –24 VDC. Other input voltage
3 V+ Red Positive DC power supply input. Typically 24 VDC. Other input voltage
Connector J5, WCB314 4-Pin QCL Load Cable
1+5V AUX Green +5V power supply output. Use pin 2 of this connector for the return. Refer to
page 10
2 GND White
3 QCL – Red Current from the QCL sinks to this pin. Refer to Figure 2.
4 QCL + (GND) Black Ground connection. QCL current sources from this pin. Refer to Figure 2.
1. Product revision is indicated by the third digit of the serial number engraved on the front panel. Refer to page 14 for transfer
functions for Revisions A through C.
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QCL OEM SERIES LOW-NOISE DRIVER
PIN DESCRIPTIONS (CONTINUED)
Table 2. Front Panel SMA Connector Descriptions
FRONT-PANEL SMA CONNECTORS
Analog In
Analog setpoint input. The voltage input on this pin sums with the onboard setpoint trimpot.
Table 3. The analog
input voltage can be negative.
Analog In GND Ground for analog setpoint input. Pin is not rated for high current return.
QCL – Current from the QCL sinks to this pin. Refer to Figure 2.
QCL + (Ground) Ground connection. QCL current sources from this pin. Refer to Figure 2.
Table 3. Current Limit Monitor and Setpoint Transfer Functions—Revision D*
FUNCTION SYMBOL QCL125 QCL500 QCL1000 QCL1500 QCL2000
Current Setpoint Monitor SET_MON 0.025 A / V 0.1 A / V 0.2 A / V 0.3 A / V 0.4 A / V
Current Output Monitor OUT_MON 0.025 A / V 0.1 A / V 0.2 A / V 0.3 A / V 0.4 A / V
Current Limit Monitor LIM_MON 0.025 A / V 0.1 A / V 0.2 A / V 0.3 A / V 0.4 A / V
Analog Input VANALOG 0.025 A / V 0.1 A / V 0.2 A / V 0.3 A / V 0.4 A / V
page 14.
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QCL OEM SERIES LOW-NOISE DRIVER
ELECTRICAL SPECIFICATIONS
PARAMETER SYMBOL MIN TYP MAX UNIT NOTE
ABSOLUTE MAXIMUM RATINGS
Positive Supply Voltage1V+ 25 VDC
If a Product Variation
PV # MAX V COMPLIANCE
PV055 +24 /
+20
PV066 ±15
±19 +11
The PV number can be found
on the front panel below the
Negative Supply Voltage1V– -25 VDC
Internal Power Dissipation2PMAX 16 W
Reference SOA charts
Operating Temperature Range2TOPR -40 to 50 ºC 35ºC max for QCL2000 OEM
Storage Temperature Range TSTG -55 to 125 ºC
Weight 2 lbs
Size 5.5 x 6.55 x 2.3 inches
PARAMETER SYMBOL MIN TYP MAX UNIT NOTE
OUTPUT CURRENT
Max Output Current IMAX A
Compliance Voltage3VCOMP 16 V with ±24 VDC power supplies
5 10 15 ppm 25ºC
5 10 15 ppm 25ºC
5 10 ppm / ºC
Delayed Start 1.25 sec
Slow Start Ramp 100 msec to full scale
Leakage Current 2 3 mA
MODULATION
Rise / Fall Time 250 / 200 nsec to full scale
Slew Rate 30 V / µsec
Depth of Modulation4
2 3
1. page 16,
2. Derating begins at 25ºC. QCL2000 maximum operating temperature is 35ºC.
supply input voltages are available by Product Variation. See page 16
page 16.
0 mA
Full Current
100% Depth of Modulation at 10 Hz
100 %
0 %
90% Depth of Modulation at 100 kHz
90
%
95 %
5 %
!
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QCL OEM SERIES LOW-NOISE DRIVER
ELECTRICAL SPECIFICATIONS, Continued
PARAMETER SYMBOL MIN TYP MAX UNIT NOTE
NOISE
RMS Noise Current
QCL500
QCL1000
QCL1500
QCL2000
0.4
1.0
1.3
µA RMS
IOUT = 500 mA
Average Noise Current Density
QCL500
QCL1000
QCL1500
QCL2000
1.0
2.0
3.0
4.0
RLOAD
IOUT = 500 mA
POWER SUPPLY
Positive Supply Voltage1V+ 22 24 25 VDC
Negative Supply Voltage1V– -22 -24 -25 VDC
250 mA
100 mA
Inrush Current Requirement2450 mA
INPUTS
Analog Input Range ANALOG -5 to +5 V
Input Pin Impedance 1000
Analog Input Damage Threshold -10 10 V
Remote Enable and
Remote Power ON
must supply min of 5 mA.
LO = DISABLED / OFF
MONITORS AND OUTPUTS
Current Setpoint Monitor Range SET_MON 0 5 V
Current Setpoint Monitor Accuracy35
Current Output Monitor Range OUT_MON 0 5 V
4
Current Monitor Stability 25 ppm
1.5 mA
Limit Monitor Range LIM_MON 0.4 V
0.1
Status Outputs
+5V AUX POWER SUPPLY OUTPUT
Output Voltage +5V AUX 5 VDC Selectable via internal
page 10
Output Current 500 mA
1. page 16,
(QCL
Current) + (Quiescent Current).
transients may damage or destroy the laser.
5. See technical note TN-LD02: “How is Current Noise Measured at Wavelength Electronics?”
operating close to the current limit.
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QCL OEM SERIES LOW-NOISE DRIVER
SAFETY INFORMATION
SAFE OPERATING AREA — DO NOT EXCEED
INTERNAL POWER DISSIPATION LIMITS
within the Safe Operating Area (SOA). Operating the unit
outside of the SOA may damage the driver and the QCL.
Operating outside of the SOA will void the warranty.
To determine if the QCL driver is suitable for your application
If you have questions about the Safe Operating Area
assistance.
!
(SOA).
USER SERVICEABLE COMPONENTS
The QCL driver is equipped with user-serviceable fuses.
Refer to page 15 if the fuses need to be replaced.
please contact the factory immediately and do not attempt
to maintain or repair the unit yourself.
THEORY OF OPERATION
The QCL Series low noise drivers are designed expressly
1
circuitry to deliver ultra-low noise current and still maintain a
wide modulation bandwidth.
the current commanded by the setpoint. The current source
between the two signals.
It may be useful to remember that you do not directly set
either with the onboard trimpots or by an external input. The
described in Table 3. The current limit is set in a similar
manner.
may increase to the point that it reaches the Compliance
Voltage limit of the current source. Once that occurs the
current source is no longer able to increase the current
driven to the load even if you increase the setpoint
The QCL OEM driver includes features that help protect
array of applications. These features are explained in detail
in the Operating Instructions.
• The user-adjustable soft-clamping current limit prevents
overdriving the laser even if the analog input signal
setpoint is above the maximum drive current for the
laser. Details on current limit function are provided on
page 9.
• Over- and under-voltage protection circuits protect the
driver and QCL if the power supply voltages fall outside
of the acceptable operating range.
• Over-temperature protection circuits safely shut down
the output if the internal temperature of the QCL driver
rises to an unsafe level.
• Output slow-start ramps the current to setpoint over
100 msec.
• A mechanical relay shorts the output connections when
The Analog Input can be used for adding to or subtracting
from the internal setpoint on the QCL OEM. Inputting
inputting negative voltages will result in subtracting from the
setpoint.
Licensed from Battelle Memorial Institute.
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QCL OEM SERIES LOW-NOISE DRIVER
OPERATING INSTRUCTIONS
These instructions are written for the most common
operating mode of the QCL driver.
according to the actual application. We recommend using a
test load until you are familiar with operation of the driver.
NECESSARY EQUIPMENT
• QCL Driver and QCL
•
recommended
•
bipolar power supply input
• Connector and cables for remote inputs and QCL output
• Connecting wires
•
We recommend using the following equipment available
•
two required
• WCB312 – power supply wiring kit
• WCB311 – 14-pin I/O Cable (included)
• WCB313 – 3-pin QCL Power Cable (included)
• WCB314 – 4-pin QCL Load Cable (included)
• QCL TEST LOAD – resistive test load for setting up and
SAFE OPERATING AREA—DO NOT EXCEED
INTERNAL POWER DISSIPATION LIMITS
The QCL driver is equipped with a heatsink that is
Refer to the online SOA calculator to determine whether or
not a fan will be necessary in your application.
!
PREVENT DAMAGE FROM ELECTROSTATIC
DISCHARGE
prevent electrostatic discharge (ESD) damage to the driver
and your laser. ESD damage can result from improper
with simple precautions.
on ESD-safe handling practices.
We recommend that you always observe ESD precautions
when handing the QCL driver and your QCL.
THERMAL MOUNTING CONSIDERATIONS
The QCL driver is equipped with internal over-temperature
protection circuitry. The FAULT LED on the front panel will
circuitry detects an internal over-temperature condition.
ventilated.
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QCL OEM SERIES LOW-NOISE DRIVER
WIRE THE POWER SUPPLIES
Wire the QCL driver to the dual power supplies as shown in
Figure 4. If you are using the PWRPAK-24V power supplies
kits WCB312 and WCB313.
AC(L) AC(N)FG-V+V AC(L) AC(N)FG-V+V
POSITIVE SUPPL
Y NEGATIVE SUPPLY
V- (Pin J4-2)
V+ (Pin J4-3)
Ground
(Pin J4-1)
Ground Interconnect
Neg-to-Pos Interconnect
Ground Wire
Twisted Pair
Chassis
Ground
150kΩ
Earth
Ground
1
1
11
2
2
2
1. Cable included as part of the WCB312 Power Supply Wiring Kit
2. Included with the QCL Driver.
Connect to AC Mains; refer to power supply
specifications for input voltage requirements.
Figure 4. QCL Power Supply Wiring
Follow these instructions to wire the power supplies using
the WCB312 and WCB313. The same method applies to
connect other power supplies to the QCL driver.
•
as shown in Figure 4.
•
terminals on the power supplies.
•
bench).
•
and V+ of Negative Supply.
• Use the remaining ring lugs to connect the power
V– terminals of the power supplies. See page 20 for
information on the WCB313 cable.
Figure 4
electronics ground is tied to earth ground at some point
USB cable connection.
This resistor provides a lossy connection from system
Some systems can have problematic ground loops. If this
POWER and ENABLE lines. It is not a requirement for low
Table 4 for
the remote Switch Settings.)
NOTE: For remote operation the front panel Power and
Enable switches must be on.
If you are unsure whether to include this resistor in your
assistance.
CONNECT THE TEST LOAD
test load rather than the actual quantum cascade laser.
Refer to page 2
instructions. Connect the test load now.
SET THE CURRENT LIMIT
The QCL driver employs a soft-clamping current limit. The
limit circuit begins to act at a current below the absolute
exceeding the absolute limit setpoint.
We recommend that setpoint is below 85% of the
current limit, because the noise level introduced into
the QCL rises when operating close to the current limit.
and 12 turns for the LIMIT trimpot.
blue POWER LED on the front panel will illuminate. Do not
enable the output at this time.
The current limit is set using the LIMIT trimpot on the front
•
referencing Table 3
VI_LIM_MON = ILIMIT / Transfer Function
© 2019 www.teamWavelength.com 10
QCL OEM SERIES LOW-NOISE DRIVER
•
• Adjust the LIMIT trimpot until the Current Limit Monitor
voltage matches the calculated VLIMIT value.
The procedure detailed here results in a practical current
limit that is somewhat below the limit calculated using the
refer to page 15.
ADJUST THE OUTPUT CURRENT
USING THE SETPOINT MONITOR
The DC current setpoint is set by adjusting the SET trimpot
•
voltage using this equation and referencing Table 3 on
page 4
VSET_MON = (IOUT
•
• Adjust the SET trimpot until the VSET_MON value on the
voltmeter matches the calculated VSET_MON value.
•
next section.
ADJUST THE OUTPUT CURRENT
USING THE CURRENT OUTPUT MONITOR
The DC current setpoint is set by adjusting the SET trimpot
•
voltage using this equation and referencing Table 3 on
page 4
VOUT_MON = IOUT / Transfer Function (V)
•
• Switch on the driver output usng the ENABLE switch.
• Adjust the SET trimpot until the VOUT_MON value on the
voltmeter matches the calculated VOUT_MON value.
•
decreased to just above the setpoint value by adjusting
the LIMIT trimpot until the voltage just begins to
decrease. Then increase the limit until the voltmeter
reads the correct VOUT_MON value again.
CONFIGURE THE +5V AUX JUMPER
Phillips screws located around the perimeter of the base of
Refer to Figure 5 on page 11 for the jumper location.
placing the jumper over both pins of the header connects
position.
Disabled.
Avoid driving noisy external circuits with the +5V AUX
output noise level if adequate precautions are not taken to
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QCL OEM SERIES LOW-NOISE DRIVER
CONFIGURE LOCAL VS. REMOTE CONTROL
NOTE: For remote operation the front panel Power and
Enable switches must be on.
The QCL driver case must be opened in order to access the
switches. The DIP switches are located on the bottom of the
Figure 5.
LOCAL ↔ REMOTE
PWR-
PWR+
EN-
EN+
+5V AUX JUMPER
LOCAL / REMOTE SWITCHES
Figure 5. Bottom View of QCL Driver Showing the
Internal Remote / Local Switches and +5V AUX Jumper
Table 4 details the switch settings for Local vs. Remote
or they can be tied to the instrument ground. Choosing
whether or not to isolate the remote Power and Enable
• Isolate the inputs when using a computer or DAQ card
to generate the control signals. Computers and DAQ
these inputs will prevent that noise from conducting to
the QCL driver and laser.
• Isolating the remote inputs requires two I/O lines per
•
wiring diagram in Figure 4.
Table 4. Local vs. Remote Switch Settings
SWITCH NO. ON (LEFT) OFF (RIGHT)
ON OFF
PWR-
PWR+
EN-
EN+
LOCAL ↔ REMOTE
4321
4Remote Signal Tied
to Driver Ground
Remote Signal
Optically Isolated
3 Local Power Switch Remote Power
Signal
2Remote Signal Tied
to Driver Ground
Remote Signal
Optically Isolated
1Local Output
Enable Switch
Remote Output
Enable Signal
and tighten the screws.
COMPLETE ADDITIONAL WIRING
If the remote power and enable functions of the QCL driver
Also connect external electronics for status monitoring.
Refer to Table 1
ANALOG SETPOINT INPUT
The external analog setpoint signal sums with the onboard
reference Table 3
VANALOG = ISETPOINT / Transfer Function
The VANALOG signal can be -5 V to +5 V.
If the analog setpoint input causes the driver to reach
page 15 for
information on current limit circuit response to modulated
analog setpoint input signals.
The bandwidth of the Current Monitor is lower than the
bandwidth of the output. To monitor the actual output
while using the resistor test load.
!
© 2019 www.teamWavelength.com 12
QCL OEM SERIES LOW-NOISE DRIVER
CONNECT THE QUANTUM CASCADE LASER
Figure 6 for proper wiring polarity.
Note that the Positive Terminal of the QC Laser is connected
Driver. The QCL driver acts as a current sink.
-V
Pin J5-4
QCL
+
Pin J5-3
QCL -
QCL Driver
Current Sink
QCL
Figure 6. QCL Wiring and Polarity
ENABLE THE QCL DRIVER OUTPUT
Enable the output current by setting the ENABLE switch to
ON (right). The blue ENABLE LED on the front panel will
illuminate. The output is disabled by setting the switch to
the OFF position (left).
RECOVER FROM A POWER SUPPLY
PROTECTION CIRCUIT FAULT
If the voltage from the dual power supplies is over or under
driver must be reset. Toggle the Power OFF then ON using
either the remote signal or front panel switch. After switching
circuits activate and the current from the power supplies
is shunted through a protection diode. The internal fuses
re-enable the driver.
RECOVER FROM AN INTERNAL
OVER-TEMPERATURE FAULT
The QCL driver is equipped with a protection circuit to switch
operating value. If an over-temperature fault is detected the
the remote output enable signal. The QCL will not allow the
output to be enabled until the internal temperature is within
the safe operating range.
© 2019 www.teamWavelength.com 13
QCL OEM SERIES LOW-NOISE DRIVER
TROUBLESHOOTING
PROBLEM POTENTIAL CAUSES SOLUTIONS
Driver will not switch on
supplies
Carefully check the wiring diagram in Figure 2 on page 2. Make sure the
power supply polarity is not reversed. The FAULT LED will illuminate red if
the driver is switched on with reversed power supply polarity.
Internal fuses are blown
fuses are not blown. Replace the fuses if necessary. Refer to page 15.
Output will not enable
switches on the QCL unit
Make sure that the Remote switches in the QCL driver are set to the correct
position for your application. Refer to Congure Local vs. Remote Control
on page 11.
Remote Enable signal is not
correct
signals are correct. Disconnect the remote input lines and check them
independently of the driver. Refer to Table 1 on page 3.
The QCL driver detected a
power supply fault
fault condition on the power supply inputs. Refer to Recover from a Power
Supply Protection Circuit Fault on page 12.
The QCL driver detected an
over-temperature condition
protection circuitry has detected an over-temperature fault condition. Refer to
page 12.
Noise current is higher than
expected
There may be ground loops
components may be higher
and shielding may be
inadequate
Refer to Wavelength Electronics Application Note AN-LD08: “Manage
Grounding to Minimize Noise with the QCL Drivers”
Also reference AN-LD09: “Troubleshooting Low Noise Systems”
Switching power supplies may
be noisy
drivers using our stock PWRPAK-24V power supplies.
unexpectedly
The QCL driver detected a
power supply fault
If the red FAULT LED is illuminated the protection circuitry has detected a
fault condition on the power supply inputs. Refer to Recover from a Power
Supply Protection Circuit Fault on page 12.
The QCL driver detected an
over-temperature condition
protection circuitry has detected an over-temperature fault condition.
Laser output power lower
than expected
Current limit set too low Using a test load (see Figure 3 on page 2) follow the procedure to set
the current limit (page 9). Verify that the current limit is suitable for your
laser by connecting the voltmeter across RLOAD
using Ohm’s Law (V = I * R).
current
QCL driver is operating in
current limit
to the output.
If I run my QCL at about
becomes non-linear and I
see distortion in my output
current waveform.
QCL driver resolution is too low Select a QCL driver with a much lower maximum output current. For
© 2019 www.teamWavelength.com 14
QCL OEM SERIES LOW-NOISE DRIVER
QCL OEM REVISION A – C WIRING DIAGRAM
Refer to Figure 7 for information on wiring earlier revisions
of the QCL driver.
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–
Optional Analog Setpoint
(-5 V to +5 V)
+
-
DVM
TTL Optional Remote Enable
HI = Enabled; Low = Disabled
ANALOG
SMA QCL
SMA
QCL
+
+
_
_
POWER
22
TTL Optional Remote Power On
HI = On; Low = Disabled
1. The Remote Power On − and Remote Enable − inputs can be optically isolated from ground.
2. The SMA connectors are electrically isolated from the QCL chassis.
1
1
V+ V−
Figure 7. Revision A – C Wiring Diagram
QCL OEM REV A – C TRANSFER FUNCTIONS
The transfer functions for production revisions A – C are
shown in Table 5 and Table 6.
Table 5. Current Limit Monitor and Setpoint Transfer
Functions—Revisions A – B
MODEL
CURRENT
OUTPUT
MONITOR
CURRENT
LIMIT
MONITOR
ANALOG
INPUT
QCL500 0.2 A / V 0.09 A / V 0.1 A / V
QCL1000 0.4 A / V 0.19 A / V 0.2 A / V
QCL1500 0.6 A / V 0.3 A / V
QCL2000 0.39 A / V 0.4 A / V
Table 6. Current Limit Monitor and Setpoint Transfer
Functions—Revision C
MODEL
CURRENT
OUTPUT
MONITOR
CURRENT
LIMIT
MONITOR
ANALOG
INPUT
QCL500 0.1 A / V 0.09 A / V 0.1 A / V
QCL1000 0.2 A / V 0.19 A / V 0.2 A / V
QCL1500 0.3 A / V 0.3 A / V
QCL2000 0.4 A / V 0.39 A / V 0.4 A / V
TECHNICAL SUPPORT
INFORMATION
This section includes useful technical information on these
• Revision A – C Wiring Diagram
• Revision A – C Transfer Functions
• Replace the Internal Fuses
• Soft-Clamp Current Limit
• Square Wave Response
• Drive LEDs With the Status Outputs
• Product Variations
• Optimizing the System for Low Noise
• Safe Operating Area Calculation
© 2019 www.teamWavelength.com 15
QCL OEM SERIES LOW-NOISE DRIVER
SOFT-CLAMP CURRENT LIMIT
The QCL driver employs a soft-clamping current limit that
begins to act at a current lower than the calculated absolute
QCL rises when operating close to the current limit.
transfer function shown in Table 3. Using the transfer
function to set the LIM_MON voltage sets the absolute
under any circumstance.
the limit circuit begins to act is oset from the calculated
LIM_MON is the current limit transfer function
for the QCL driver model you are using (see Table 3
LIM_MON * (VLIM_MON – 0.4) (A)
analog input setpoint is nonlinear. The result is that the drive
current will asymptotically approach the absolute current
setpoint voltage far exceeds the current limit voltage.
Figure 9 illustrates the behavior of the soft-clamp current
limit. In this case the analog input voltage setpoint signal is
attempt to overdrive the current limit.
Figure 9. Soft Clamping Current Limit Behavior
REPLACE THE INTERNAL FUSES
The QCL driver is equipped with two internal fuses. If the
replace these two fuses. See Figure 8 for the fuse location.
screws around the base of the unit. Then remove the
LOCAL ↔ REMOTE
PWR-
PWR+
EN-
EN+
Figure 8. Location of Internal Fuses
tighten the eight screws.
© 2019 www.teamWavelength.com 16
QCL OEM SERIES LOW-NOISE DRIVER
SQUARE WAVE RESPONSE
Figure 10 and Figure 11 illustrate the modulation response
Figure 10. 10 kHz Output Plot
QCL1000 at 1.15 A with 10 Ω Test Load
Figure 11. 600 kHz Output Plot
QCL1000 at 1.15 A with 10 Ω Test Load
DRIVE LEDS WITH THE STATUS OUTPUTS
LEDs. Assuming VF= 2 V and a drive current requirement
Figure 12. Adjust the
resistor value to match the current and voltage requirements
of the LED.
1 kΩ, 1/4 W
Ground
(Pin J1:3)
Status Output
(Pin J1:7, 8, or 9)
LED
Figure 12. Wiring Status LEDs
PRODUCT VARIATIONS
that gives us the unique ability to modify our drivers and
controllers to suit exactly your application. Our Product
long-term high-volume manufacturing.
•
requires power supply inputs of +24 V and –30 V.
•
to maximize stability in an OEM laser controller.
•
space constraints of your electronics chassis.
• Increase the maximum output current.
•
supply input voltage of ±15 V results in an output
Contact Sales for information on how a Product Variation
can be applied in your situation.
REVERSE POLARITY UNIT AVAILABLE
in the OEM package.
Figure 13 below.
QCLSTANDARD QCL(+)
Figure 13. Polarity Comparison
More detailed information is available in the
QCL OEM(+) Series datasheet.
-V
Pin J5-4
QCL +
Pin J5-3
QCL -
QCL Driver
Current Sink
QCL
Pin J5-4
QCL-
Pin J5-3
QCL+
QCL(+) Driver
Current Source
V+
QCL
GND
© 2019 www.teamWavelength.com
QCL OEM SERIES LOW-NOISE DRIVER
OPTIMIZING THE SYSTEM FOR LOW NOISE
The QCL driver is designed to deliver extremely low noise
must also be considered for optimum system performance.
Wavelength Electronics provides a number of resources on
our website that will help you understand noise sources and
performance is the power supply used to power the QCL
driver. Wavelength has extensively tested the TDK/Lambda
supply for most QCL applications (available as our part
Proper grounding technique is also critical. Always ensure
there are no ground loops within the system. Grounding the
Figure 14 through Figure 16
high-quality switching power supplies and grounding the
chassis.
Floating Chassis, Linear Power Supply
Frequency (Hz)
Noise Current Density (nA / √Hz)
100101102103104105106
100
101
102
60 Hz Noise
Figure 14. Noise Plot with Floating Chassis and
Linear Power Supplies
Leaving the chassis ungrounded and using a low-quality
signature on the output. In most applications this strong
so it is critical to ground the chassis to achieve the best
system performance.
Grounded Chassis, Linear Power Supply
Frequency (Hz)
Noise Current Density (nA / √Hz)
100101102103104105106
100
101
102
60 Hz Noise
Figure 15. Noise Plot with Grounded Chassis and Linear
Power Supplies
Grounded Chassis, Switching Power Supply
Frequency (Hz)
Noise Current Density (nA /
√
Hz)
10010110210310410510
6
100
101
102
60 Hz Noise
Figure 16. Noise Plot with Grounded Chassis and High
Quality Switching Power Supplies
•
supplies independent of the laser driver system in order
to ensure they are performing at a level that will not
introduce unacceptable noise.
•
such as the TDK/Lambda MAW Series will provide a
• Use low-noise analog input signal generators. Even
noise signature that may negatively impact system
performance.
•
wire the fan to the same power supplies used to power
the driver. Fans are notoriously noisy.
•
connectors.
© 2019 www.teamWavelength.com
QCL OEM SERIES LOW-NOISE DRIVER
SAFE OPERATING AREA CALCULATION
The Safe Operating Area of the QCL is determined by the
amount of power that can be dissipated within the output
stage of driver. If that power limit is exceeded permanent
damage can result.
!
Refer to the Wavelength Electronics website for the most
up-to-date SOA calculator for our products. The online tool
operating temperature.
SOA charts are included in this datasheet for quick
reference. We recommend you use the online tools instead.
Follow these steps to determine if the driver will be operating
within the SOA.
•
voltage (VQCL) and current (IMAX
•
VDROP = |V-| - VQCL (V- is the negative power supply
voltage)
• Mark VDROP
• Mark IMAX
until it intersects the VDROP line.
•
voltage.
• Extend a diagonal line from V- to the intersection of the
• If the Load Line crosses the Safe Operating Area line at
If the SOA calculator indicates the QCL will be outside of the
less power is dissipated within the driver. See Wavelength
Electronics Application Note AN-LDTC01: The Principle of
the Safe Operating Area for information on shifting the Load
Line.
SOA to make sure the controller will operate safely. If you
contact Wavelength Electronics for assistance.
QCL500 SAFE OPERATING AREA
The QCL500 will safely operate over the full drive current
the online SOA calculator.
over the heatsink in order to safely operate.
0 5 10 15 20 25
0.0
0.2
0.4
0.6
0.8
1.0
Airflow Required
Voltage Drop (|V–| - VQCL)
Current (A)
Figure 17. QCL1000 SOA Chart, at 25ºC
0 5 10 15 20 25
0
0.3
0.6
0.9
1.2
1.5
Airflow Required
Voltage Drop (|V–| - V
QCL
)
Current (A)
Unsafe
Figure 18. QCL1500 SOA Chart, at 25ºC
0 5 10 15 20 25
0
0.4
0.8
1.2
1.6
2
Airflow Required
Voltage Drop (|V–| - V
QCL
)
Current (A)
Unsafe
Figure 19. QCL2000 SOA Chart, at 25ºC
© 2019 www.teamWavelength.com 19
QCL OEM SERIES LOW-NOISE DRIVER
CABLE SPECIFICATIONS
WCB311 — 14-PIN I/O CABLE; ONE INCLUDED WITH QCL OEM DRIVER
STRIP 5.00" OF
PVC JACKET
TYP, THIS END
BLK
RED
BRN
WHT
ORN
GRN
BLU
RED
GRN
WHT
BLK
BLK
RED
POSITION 14 OPEN
POSITION 1 OPEN
POSITION 2 OPEN
Overall Cable Length 18”
14-pin MOLEX
50-57-9414
Optional connections for Analog In Setpoint
Monitor Ground
LIM_MON
OUT_MON
SET_MON
Overtemp Status
Power Status
Enable Status
Remote Enable +
Remote Enable –
Remote Power On +
Remote Power On –
Analog In GND
Analog In
Reserved - Do Not Connect
3
4
5
6
7
8
9
10
11
12
13
1
2
14
WCB312 — POWER SUPPLY WIRING KIT
24” Long Twisted Pair, 14 AWG
2 Sets Provided Per WCB312 Kit
Black for Line, White for Neutral
Negative-to-Positive Interconnect, 10”, 24 AWG
Power Supply Ground Interconnect, 10”, 14 AWG
Power Supply Ground Wire, 10”, 24 AWG
• (6) blue lugs for 14 AWG wire
• (3) red lugs for 24 AWG wire.
Figure 4 on page
9
•
Figure
4 on page 9
•
the power supplies.
•
•
V+ of the Negative Supply.
•
© 2019 www.teamWavelength.com 20
QCL OEM SERIES LOW-NOISE DRIVER
WCB313 — 3-PIN QCL POWER CABLE; ONE INCLUDED WITH QCL OEM DRIVER
STRIP 5.00" OF
PVC JACKET
TYP, THIS END
BLK
WHT
RED
1
Overall Cable Length 18”
3-pin MOLEX
SDA-43645-0300
2
3
PGND
V–
V+
WCB314 — 4-PIN QCL LOAD CABLE; ONE INCLUDED WITH QCL OEM DRIVER
STRIP 5.00" OF
PVC JACKET
TYPE, THIS END
RED
BLK
GRN
WHT
POSITION 1 OPEN
POSITION 2 OPEN
1
Overall Cable Length 18”
4-pin MOLEX
SDA-43645-0400
Optional connections for +5V AUX output
4
3
2
+5V AUX
QCL+
QCL–
GND, Low Current
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