LDP
3840B

1

Specifications

Product Features
Precision pulsed current to 3A
Clean current pulses with fast risetimes (<50nS) and low overshoot(<5%)

Precision Pulsed
Current Source

Built-in laser diode protection
Adjustable pulse width, duty cycle,
and frequency
User-selectable pulse polarity
Accepts external trigger tocontrol pulses and provides a
trigger to initiate corresponding
measurements
GPIB/IEEE-488 interface

www.ilxlightwave.com

The new LDP-3840B Precision Pulsed current source
is a microprocessor-based instrument specifically designed
for pulse testing and characterizing laser diodes. The
LDP-3840B provides up to 3A of peak pulse current withadjustable pulse widths from 100ns to 10ms.
Careful attention to design for clean pulses at laser diodeload levels provides a low noise pulsed current with fast risetimes while maintaining overshoot of less than 5%.
Testing and characterization can be automated with the
3840B through the GPIB/IEEE interface. For basic system
integration, a trigger can be used to control pulses andinitiate corresponding measurements without a commandprogram.
Like all ILX Lightwave laser diode control instruments,
the LDP-3840B incorporates laser diode protection andsafety features such as current limits, output shorting circuits,
AC line filters, and double-shielded transformers to help
suppress laser damaging transients.

An Affordable Precision Pulsed Current Source for
Testing and Characterizing Laser Diodes

For information call
P.O. Box 6310, Bozeman, MT 59771 • FAX: 406-586-9405

Preliminary

1-800-459-9459
International Inquiries: 406-586-1244
email: sales@ilxlightwave.com
Rev02.070805

LDP

3840B
Precision Pulsed
Current Source

LDP
3840B
Precision Pulsed
Current Source

At the heart of the LDP-3840B is a precisionpulsed current source that delivers clean pulses
with low overshoot and fast rise and fall times. The
3840B’s low noise, transient-suppressed output isdesigned specifically for laser diode load levels.
Digital control of pulse width, duty cycle andfrequency provide quick and easy control of pulse
parameters for maximum flexibility in varying test
applications.
For accurate monitoring of laser drive parameters in LIV applications, laser diode mounting
boards are available with 50Ω terminated connections for voltage and current monitoring.

Laser Diode Protection
One of the most important features of the
LDP-3840B is ILX Lightwave’s proven laser diodeprotection features including current limits andredundant output shorting circuits. During powerup, the laser diode is protected from current transients by a careful turn-on sequence. AC line filtersand double shielded transformers provide furthertransient protection during laser operation.

Pulse Tuning for Optimum
Performance
The LDP-3840B offers a method to optimize
the pulse response of the instrument to the laser
diode load. By matching the source to load
impedance at the laser diode through the additionof a small series resistance, unwanted parasitic
effects can be compensated for to reduce ringing
and overshoot on the pulse. In conjunction withthe 3840B, ILX Lightwave has developed a laser
mounting board to easily fixture the laser diodeand to aid in tuning for optimal pulses.

Tuned response of the LDP-3840B.

Convenient Features Make Your
Work Easier and More Reliable
The intuitive front panel of the LDP-3840B is
designed for quick and easy instrument operation
permitting precise pulse control. Pulse modes andparameters are logically grouped together without
confusing multifunction keys allowing easy adjustment of pulse width, duty cycle and frequency. A
selection of instrument operating modes includes
pulse polarity, constant duty cycle and constantpulse repetition interval (PRI). In constant duty
cycle mode, the set duty cycle is maintained while
adjusting pulse widths. In constant PRI mode, theset pulse interval is maintained while adjusting
pulse width.
The bright 4-digit LED display is easy to view inlaboratory environments. Precision digital tuning
is easy with the front panel adjustment knob.

Complete System Integration
Speed up data gathering with more repeatable, accurate control for automated testing
and characterization of laser diodes with the
GPIB/IEEE-488 interface. All instrument functions
accessible from the front panel are also accessible
through the GPIB interface.
TTL level triggers are incorporated into the
LDP-3840B to control output pulses and to initiate
corresponding measurements from other instruments without a command program.

Selectable Pulse Polarity

Untuned pulsed output.

LDP

Specifications1

Precision Pulse Control for Laser
DiodesDepending on the configuration of the laser
diode under test, the LDP-3840B allows the output
polarity to be quickly configured for either anodeor cathode grounded devices from the front panelor through the GPIB/IEEE interface. ILX’s laser
diode mounting board can be configured for either
polarity with the laser correctly installed.

PULSE AMPLITUDE

GENERAL

Output Current Range:
0 to 3000mA
Setpoint Resolution:
1000µA
Setpoint Accuracy (% of FS):2 ±2.5%
Compliance Voltage:
10V maximum
Overshoot:<5%
Noise and Ripple (µA rms):
500µA

Chassis Ground:Power Requirements:

PULSE PARAMETERS
Pulse Width
Range:
Resolution:
Accuracy:
Rise/Fall Time:3
Polarity:4

100ns to 10ms
100ns
-35 to 10ns ±0.01% of FS±50ns
Positive or negative

PULSE REPETITION INTERVAL (PRI)
Range
Internal:
External:
Resolution:
Accuracy:
Duty Cycle:

1µs to 100ms
1µs to single shot
1µs
20ns ±0.01%
10% maximum

TRIGGER OUTPUT
Type:
Connector:
Jitter:
Display:

TTL
BNC
±5ns
100ns ±10ns

TTL
BNC±100ns
290ns ±20ns

ANALOG OUTPUT
Transfer Function:
Connector:

Weight:Operating Temperature:
Storage Temperature:
Humidity:
Laser Safety Features:

NOTES
1. All specifications measured at 25°C after a one-hour warm-up period with an
ILX LPB Laser Mounting Board, unless otherwise specified.
2. Accuracy measurements from 10% to full scale output.
3. Measured from 10% to 90% points at half scale output with the typical being
25ms.
4. Polarity selected via the front panel or through GPIB.
In keeping with our commitment to continuing improvement, ILX Lightwave
reserves the right to change specifications without notice and without liability forsuch changes.

ORDERING INFORMATION
LDP-3840*
LPB-380
LPC-388
CC-380Precision Pulsed Current Source, 3A
Laser Mounting Board
Current/Voltage Monitor Cable
Output Cable 3Ω

LabVIEW® Instrument Driver
LabVIEW® is a registered trademark of National Instruments.

TRIGGER INPUTType:
Connector:
Jitter:Delay:

Size (HxWxD):

4mm banana jack
50/60Hz
100-120VAC ±10%220-240VAC ±10%88mm X 185mm X 304mm(3.5" x 7.3" x 12")
3.6kg (8lbs)
10°C to 40°C
–40°C to 70°C
<85% relative
Interlock3.33V/A, 10V full scale
BNC*Each LDP-3840B comes with an LPB-380 Mounting Board and a CC380 3Ω Output Cable. Additional mounting boards and output cables
can be ordered.

3840B
Precision Pulsed
Current Source

LDP
3840B
Precision Pulsed
Current Source

At the heart of the LDP-3840B is a precisionpulsed current source that delivers clean pulses
with low overshoot and fast rise and fall times. The
3840B’s low noise, transient-suppressed output isdesigned specifically for laser diode load levels.
Digital control of pulse width, duty cycle andfrequency provide quick and easy control of pulse
parameters for maximum flexibility in varying test
applications.
For accurate monitoring of laser drive parameters in LIV applications, laser diode mounting
boards are available with 50Ω terminated connections for voltage and current monitoring.

Laser Diode Protection
One of the most important features of the
LDP-3840B is ILX Lightwave’s proven laser diodeprotection features including current limits andredundant output shorting circuits. During powerup, the laser diode is protected from current transients by a careful turn-on sequence. AC line filtersand double shielded transformers provide furthertransient protection during laser operation.

Pulse Tuning for Optimum
Performance
The LDP-3840B offers a method to optimize
the pulse response of the instrument to the laser
diode load. By matching the source to load
impedance at the laser diode through the additionof a small series resistance, unwanted parasitic
effects can be compensated for to reduce ringing
and overshoot on the pulse. In conjunction withthe 3840B, ILX Lightwave has developed a laser
mounting board to easily fixture the laser diodeand to aid in tuning for optimal pulses.

Tuned response of the LDP-3840B.

Convenient Features Make Your
Work Easier and More Reliable
The intuitive front panel of the LDP-3840B is
designed for quick and easy instrument operation
permitting precise pulse control. Pulse modes andparameters are logically grouped together without
confusing multifunction keys allowing easy adjustment of pulse width, duty cycle and frequency. A
selection of instrument operating modes includes
pulse polarity, constant duty cycle and constantpulse repetition interval (PRI). In constant duty
cycle mode, the set duty cycle is maintained while
adjusting pulse widths. In constant PRI mode, theset pulse interval is maintained while adjusting
pulse width.
The bright 4-digit LED display is easy to view inlaboratory environments. Precision digital tuning
is easy with the front panel adjustment knob.

Complete System Integration
Speed up data gathering with more repeatable, accurate control for automated testing
and characterization of laser diodes with the
GPIB/IEEE-488 interface. All instrument functions
accessible from the front panel are also accessible
through the GPIB interface.
TTL level triggers are incorporated into the
LDP-3840B to control output pulses and to initiate
corresponding measurements from other instruments without a command program.

Selectable Pulse Polarity

Untuned pulsed output.

LDP

Specifications1

Precision Pulse Control for Laser
DiodesDepending on the configuration of the laser
diode under test, the LDP-3840B allows the output
polarity to be quickly configured for either anodeor cathode grounded devices from the front panelor through the GPIB/IEEE interface. ILX’s laser
diode mounting board can be configured for either
polarity with the laser correctly installed.

PULSE AMPLITUDE

GENERAL

Output Current Range:
0 to 3000mA
Setpoint Resolution:
1000µA
Setpoint Accuracy (% of FS):2 ±2.5%
Compliance Voltage:
10V maximum
Overshoot:<5%
Noise and Ripple (µA rms):
500µA

Chassis Ground:Power Requirements:

PULSE PARAMETERS
Pulse Width
Range:
Resolution:
Accuracy:
Rise/Fall Time:3
Polarity:4

100ns to 10ms
100ns
-35 to 10ns ±0.01% of FS<50ns
Positive or negative

PULSE REPETITION INTERVAL (PRI)
Range
Internal:
External:
Resolution:
Accuracy:
Duty Cycle:

1µs to 100ms
1µs to single shot
1µs
20ns ±0.01%
10% maximum

TRIGGER OUTPUT
Type:
Connector:
Jitter:
Display:

TTL
BNC
±5ns
100ns ±10ns

TTL
BNC±100ns
290ns ±20ns

ANALOG OUTPUT
Transfer Function:
Connector:

Weight:Operating Temperature:
Storage Temperature:
Humidity:
Laser Safety Features:

NOTES
1. All specifications measured at 25°C after a one-hour warm-up period with an
ILX LPB Laser Mounting Board, unless otherwise specified.
2. Accuracy measurements from 10% to full scale output.
3. Measured from 10% to 90% points at half scale output with the typical being
25ms.
4. Polarity selected via the front panel or through GPIB.
In keeping with our commitment to continuing improvement, ILX Lightwave
reserves the right to change specifications without notice and without liability forsuch changes.

ORDERING INFORMATION
LDP-3840*
LPB-380
LPC-388
CC-380Precision Pulsed Current Source, 3A
Laser Mounting Board
Current/Voltage Monitor Cable
Output Cable 3Ω

LabVIEW® Instrument Driver
LabVIEW® is a registered trademark of National Instruments.

TRIGGER INPUTType:
Connector:
Jitter:Delay:

Size (HxWxD):

4mm banana jack
50/60Hz
100-120VAC ±10%220-240VAC ±10%88mm X 185mm X 304mm(3.5" x 7.3" x 12")
3.6kg (8lbs)
10°C to 40°C
–40°C to 70°C
<85% relative
Interlock3.33V/A, 10V full scale
BNC*Each LDP-3840B comes with an LPB-380 Mounting Board and a CC380 3Ω Output Cable. Additional mounting boards and output cables
can be ordered.

3840B
Precision Pulsed
Current Source

LDP
3840B

1

Specifications

Product Features
Precision pulsed current to 3A
Clean current pulses with fast risetimes (<50nS) and low overshoot(<5%)

Precision Pulsed
Current Source

Built-in laser diode protection
Adjustable pulse width, duty cycle,
and frequency
User-selectable pulse polarity
Accepts external trigger tocontrol pulses and provides a
trigger to initiate corresponding
measurements
GPIB/IEEE-488 interface

www.ilxlightwave.com

The new LDP-3840B Precision Pulsed current source
is a microprocessor-based instrument specifically designed
for pulse testing and characterizing laser diodes. The
LDP-3840B provides up to 3A of peak pulse current withadjustable pulse widths from 100ns to 10ms.
Careful attention to design for clean pulses at laser diodeload levels provides a low noise pulsed current with fast risetimes while maintaining overshoot of less than 5%.
Testing and characterization can be automated with the
3840B through the GPIB/IEEE interface. For basic system
integration, a trigger can be used to control pulses andinitiate corresponding measurements without a commandprogram.
Like all ILX Lightwave laser diode control instruments,
the LDP-3840B incorporates laser diode protection andsafety features such as current limits, output shorting circuits,
AC line filters, and double-shielded transformers to help
suppress laser damaging transients.

An Affordable Precision Pulsed Current Source for
Testing and Characterizing Laser Diodes

For information call
P.O. Box 6310, Bozeman, MT 59771 • FAX: 406-586-9405

Preliminary

1-800-459-9459
International Inquiries: 406-586-1244
email: sales@ilxlightwave.com
Rev02.070805

LDP

3840B
Precision Pulsed
Current Source