THORLABS IP250-BV User manual

IP250-BV
250 mA Blue Laser Diode
Controller
User Guide

IP250-BV Blue Laser Diode Controller
Table of Contents
Chapter 1Overview............................................................................ 1
1.1.Features........................................................................1
Chapter 2Setup and Operation ........................................................2
2.1.Connections...................................................................2
2.2.Operation......................................................................3
2.2.1.Automatic Constant Current Control (ACC).................................3
2.2.2.Automatic Constant Power Control (APC)...................................5
2.2.3.Analog Modulation.......................................................................6
2.2.4.Remote Control Inputs.................................................................7
2.3.AlarmsandTroubleshooting..........................................7
2.4.RemoteMonitoring.......................................................8
2.5.Accessories....................................................................8
Chapter 3Specifications ...................................................................9
Chapter 4Output Derating Curves................................................. 11
Chapter 5Regulatory.......................................................................12
5.1.WasteTreatmentisYourOwnResponsibility...............12
5.2.EcologicalBackground.................................................12
Chapter 6Thorlabs Worldwide Contacts.......................................13

IP250-BV Blue Laser Diode Controller Chapter 1: Overview
Rev F, October 24, 2017 Page 1
Chapter 1 Overview
The IP250-BV is a 250 mA (medium power), board level laser diode controller
optimized for the higher operating voltages of the blue and the blue-violet laser
diodes. The driver is in the form of a PCB assembly with provisions for mounting
into other higher-level assemblies. It can accommodate only common cathode
(cathode grounded) laser diode pin-out configurations, and it allows control of the
laser by means of either constant current or constant power modes. The driver
contains circuitry for complying with the various laser safety requirements, as well
as protection circuitry for the laser diode.
The primary application for this product is to provide a method of precisely
controlling a blue or blue-violet laser diode at the PCB board level or within the
confines of a higher level assembly. In all cases, the end-user must provide DC
power and the proper connections between the unit and the laser diode. In addition
to this, the end-user is responsible for the proper limit settings needed for their
particular laser diode and application.
1.1. Features
250 mA Blue Laser Diode Driver
Also Recommended for Driving LEDs
Input Power ±12 VDC @ 275 mA
Control Range: 0 to ±250 mA (CC), 5 μA to 2 mA (CW)
0 to 10 V Analog Modulation Bandwidth: DC to 50 kHz
Optimized for Lasers with Vop greater than 5 V

IP250-BV Blue Laser Diode Controller Chapter 2: Setup and Operation
Page 2 10713-D02
Chapter 2 Setup and Operation
2.1. Connections
Wiring harnesses have been provided to make the proper connections from the
IP250-BV to its power source and the laser diode to be driven. One harness has a
three-pin connector mate the other has a four-pin connector mate.
The wire harness made with the 3-pin connector should be connected to J1 of the
IP250-BV and the ±12 V power supply. Connect to the power supply as follows:
Power Supply
Connector Wire Color Designation
J1-1 Red +12 V
J1-2 Black Common
J1-3 Yellow -12 V
The wire harness made with the 4-pin connector should be connected to J2 of the
IP250-BV and the laser diode to be driven. Connect the laser diode as follows:
Laser Diode Connections
Connector Wire Color Designation
J2-1 Blue Laser Anode
J2-2 Black Laser Cathode Ground
J2-3 Black Monitor Photodiode Cathode
J2-4 Orange Monitor Photodiode Anode
Note: Either the monitor photodiode cathode or monitor photodiode anode MUST
be connected to ground somewhere in this system. Typically this is done at the
laser diode package itself on a common pin. To eliminate errors due to wire losses,
always return the photodiode ground connection on the wire provided. Do not use
a common wire for the photodiode and laser diode ground currents.
If the photodiode is completely isolated from the laser diode, install a wire jumper
into J3 of the IP250-BV to fix the ground connection to the photodiode cathode.
Refer to Figure 1 on Page 4 for the schematic diagram detailing the laser diode
connections.
This driver is limited to common-cathode (cathode grounded) laser diodes.

IP250-BV Blue Laser Diode Controller Chapter 2: Setup and Operation
Rev F, October 24, 2017 Page 3
Figure 1 Laser Diode Connections
2.2. Operation
2.2.1. Automatic Constant Current Control (ACC)
1. This board will only work with laser diodes with grounded cathodes.
2. Set JMP2 to “ACC” for Constant Current operation. JMP2 is located on
the left side of the unit. Always disable the laser driver prior to changing
modes.
3. Refer to output current derating curves in Appendix A before proceeding.
4. Apply power to the unit.

IP250-BV Blue Laser Diode Controller Chapter 2: Setup and Operation
Page 4 10713-D02
5. Using a digital multimeter measure the ILIM Test point with respect to the
TP GND Test point (all measurements will be with respect to TP GND).
Adjust the ILIM ADJ potentiometer for the maximum current that the laser
must be limited to. The transfer function is 1 V = 1 A, with a maximum
adjustment of approximately 0.250 V or 250 mA.
6. If a monitor photodiode (MPD) is connected, measure the PLIM Test point
and adjust the PLIM ADJ pot for the maximum MPD current expected.
The transfer function is 1 V = 1 mA, with a maximum adjustment of 2.5 V
or 2.5 mA.
When operating in ACC the PLIM (power limit) function is still active if the
MPD current reaches the limit point. This is especially helpful if the laser
is to be operated at varying temperatures where the efficiency may
change to the point where the operating current will overdrive the laser.
The PLIM will always keep the laser in a safe operating area when
properly set.
If no MPD is connected always set the PLIM ADJ fully clockwise.
7. The P/I ADJ Pot will allow adjustment of the laser drive current from 0 mA
to the ILIM set point or 250 mA max. When turning on a laser for the first
time it is suggested that this pot be set fully counterclockwise.
8. Press and release the ENABLE switch.
9. The green LD ON indicator will turn on.
NOTE: There will always be a delay until full power of approximately 2 to
3 seconds before any current can flow to the laser diode.
10. Adjust the P/I ADJ potentiometer clockwise to increase the injection
current of the laser diode. The Ild Test point provides an analog read back
of the actual laser current, 1 V = 1 A. The Ipd Test point provides an
analog read back of the Photodiode monitor current, 1 V = 1 mA and can
be used to gauge the relative output power of the laser.
11. Pressing the ENABLE switch while the laser is operating will turn off the
laser current.
If the ALARM indicator turns ON see “Alarms and Troubleshooting” below.
NOTE: If the ILIM setting is below approximately 10 mA the I LIMIT LED will be
ON, this is normal.
If the current is adjusted to its maximum limit then the I LIMIT indicator will turn
ON. This indicator is active when the injection current is approximately 95% of the
maximum limit.
If the photodiode is connected and the PLIM is set to a value requiring less than
the maximum current set by ILIM, the I LIMIT indicator will NOT turn ON and the
unit will operate in constant power at the power limit level set by PLIM.

IP250-BV Blue Laser Diode Controller Chapter 2: Setup and Operation
Rev F, October 24, 2017 Page 5
While operating in APC Mode, if the power is adjusted to its maximum limit then
the injection current will not increase even though the potentiometer has more
adjustment.
2.2.2. Automatic Constant Power Control (APC)
Photodiode feedback current is required in APC Mode.
1. Set JMP2 to “APC” for constant current operation. JMP2 is located on the
left side of the unit. Always disable the laser driver prior to changing
modes.
2. Apply power to the unit.
3. Using a digital multimeter measure the ILIM Test point with respect to the
TP GND Test point (all measurements will be with respect to TP GND).
Adjust the ILIM ADJ potentiometer to the maximum laser current limit.
The transfer function is 1 V = 1 A, with a maximum adjustment of
approximately 0.250 V or 250 mA.
When operating in APC the ILIM (current limit) function is still active if the
laser current reaches the limit point.
4. Measure the PLIM Test point and adjust the PLIM ADJ pot for the
maximum MPD current expected. The transfer function is 1 V= 1 mA, with
a maximum adjustment of 2.5 V or 2.5 mA.
5. The P/I ADJ Pot will allow adjustment of the monitor photodiode current
from 5 uA to the PLIM set point or 2 mA max. When turning on a laser for
the first time it is suggested that this pot be set fully counterclockwise.
6. Press and release the ENABLE switch.
7. The green LD ON indicator will turn ON. If the ALARM indicator turns ON
see “Alarms and Troubleshooting” below. If the I LIMIT indicator turns ON
immediately press the ENABLE switch and refer to “Alarms and
Troubleshooting”.
8. Adjust the P/I ADJ potentiometer clockwise to increase the MPD current.
The IPD Test point provides an analog read back of the actual MPD
current, 1 V = 1 mA.
9. Pressing the ENABLE switch while the laser is operating will turn off the
laser current.
While operating in APC Mode, if the power is adjusted to its maximum limit then
the injection current will not increase even though the potentiometer has more
adjustment.
If the PLIM is set to a value that requires a higher level of drive current than ILIM
is set to, the I LIMIT indicator will turn ON and the unit will operate in constant
current at the current limit level.

IP250-BV Blue Laser Diode Controller Chapter 2: Setup and Operation
Page 6 10713-D02
If the Photodiode is connected incorrectly or the connection is opened, the I LIMIT
indicator will turn ON and the unit will operate in constant current at the current
limit level.
2.2.3. Analog Modulation
The amplitude of the laser injection current can be varied over time by connecting
a signal generator to the BNC connector J3 on the IP250-BV. It is recommended
that the unit be configured to operate in ACC mode whenever analog modulation
is used.
J3 can also be used as a remote analog input, allowing the user to program the
laser injection current from 0 to 250 mA by applying a 0 to 10 VDC signal. The
transfer function being 25 mA per 1 V.
The P/I ADJ pot must be set fully counterclockwise prior to using this input.
For 100% depth of modulation set the P/I ADJ pot fully counterclockwise and apply
a sine wave input to J3. The peak-to-peak amplitude must equal ILIM / 0.025 and
a DC offset equal to 0.5 of the amplitude must be applied (the signal should always
be above 0 V).
The depth of modulation can be decreased by increasing the P/I ADJ pot to provide
a DC current offset, and then adjusting the peak-to-peak amplitude to stay within
the ILIM range. The ILIM circuit will limit the average current to the ILIM setting
and the I LIMIT indicator will turn on when the average current exceeds the ILIM
setting.
The ILD Test point will provide the average current level when modulating.

IP250-BV Blue Laser Diode Controller Chapter 2: Setup and Operation
Rev F, October 24, 2017 Page 7
2.2.4. Remote Control Inputs
In addition to the automatic shutdown features, the IP250-BV also has a number
of remote enable and lockout functions accessible on J4 of the unit. The standard
unit provides a shunt jumper installed in J4 Pins 5-6. This is the remote lockout
input and must be shorted in order for the unit to be ENABLED. A summary of the
J4 functions is provided for reference. A mating wire harness is available from
Thorlabs should you decide to incorporate these features (refer to Accessories for
more information):
Pin Description
J4-1 Remote Enable Input
J4-2 Remote Enable Return (common to ground)
Momentarily connecting J4-1 to J4-2 will allow remote enable and disable the unit.
Leave unconnected when not using.
Pin Description
J4-3 Key lock Input
J4-4 Key Lock Return (common to ground)
A closed connection across J4-3 to J4-4 will prevent the unit from being ENABLED.
Leave unconnected when not using.
Pin Description
J4-5 Remote Interlock Input
J4-6 Remote Interlock Return (common to ground)
An open connection across J4-5 to J4-6 will prevent the unit from being ENABLED.
These two points must be connected for unit to operate.
All connections to J4 must be made using isolated or dry contacts (i.e. switches or
relays with no potentials on the contacts).
2.3. Alarms and Troubleshooting
This unit contains circuitry that will automatically shut down the laser driver if any
of the following conditions are met:
The laser diode anode and cathode connections are reversed.
The laser diode connection is broken or an open circuit exists.
The operating voltage (Vop) of the laser exceeds approximately 8 V.
If an alarm shutdown occurs the ALARM indicator will turn ON and the LD ON
indicator will turn OFF, remove power from the unit, correct the problem, and
reapply power to the unit. Pressing the ENABLE switch once will turn the ALARM
indicator OFF. Pressing it again will re-enable the unit.

IP250-BV Blue Laser Diode Controller Chapter 2: Setup and Operation
Page 8 10713-D02
In addition to the alarm shutdown, the IP25-BV will also shutdown (or not allow
ENABLE) if any of the following conditions exist or occur:
The Key lock Inputs (J4-3 and J4-4) are shorted together.
The Remote Interlock Inputs (J4-5 and J4-6) are open circuit.
The -12 V power supply is below approximately -10.8 V (-3.6 V typical).
As mentioned above, the I LIMIT indicator will turn ON when the laser injection
current exceeds 95% of the ILIM setting. This could be due to a number of
conditions summarized here:
The current or power has been adjusted to a point that requires an
injection current of greater than 95% of the current limit setting.
The photodiode is reverse connected (in PMODE operation).
Identified by a negative level at the IPD Test point.
The photodiode is not connected (in PMODE operation).
Identified by 0 V at the IPD Test point.
The photodiode is short-circuited (in PMODE operation).
Identified by 0 V at the IPD Test point.
The ILIM pot is set full CCW (minimal).
2.4. Remote Monitoring
J5 has been reserved as an I/O port for specialized applications incorporating the
IP250-BV. Refer to the attached engineering support drawing and contact a
Thorlabs engineer for more specific information on using these connections.
2.5. Accessories
The IP250-BV is shipped with the wire harness mates for J1 and J2. You may
purchase spare or replacement harnesses from Thorlabs as well as a suitable wire
harness for J4. The part numbers are listed below:
Wire Harness Descriptions
Jumper Description Connector Description
J1 DC Input Wires Molex 70543-0002
J2 LD Wire Harness Molex 70543-0003
J3 Modulation Input BNC
J4 Status Wire Harness Molex 70543-0005
J5 Test Points Standard 0.1” Spaced Header

IP250-BV Blue Laser Diode Controller Chapter 3: Specifications
Rev F, October 24, 2017 Page 9
Chapter 3 Specifications
Specification Value
Input Power ±12 VDC @ 275 mA
Constant Current Mode
Control Range 0 to ±250 mA
Setting Accuracy ±0.5 mA
Compliance Voltage >8.0 VDC
Ripple and Noise (10 Hz - 10 MHz) <10 μA RMS
Short-time Fluctuations <50 μA
Temperature Coefficient <100 ppm/°C
Drift (30 min. <10 Hz) <100 μA
Limit Adjust Range 0 to 250 mA
Limit Accuracy ±1% of Limit Setpoint
Constant Power Mode
Control Range Photo Diode Current 5 μA to 2 mA
Setting Accuracy ±2 μA
Drift (30 min. <10 Hz) <1 μA
Limit Adjust Range 0 to >2.5 mA
Limit Accuracy ±2 μA
Analog Modulation / Control Voltage
Input Resistance 10 kΩ
Bandwidth DC to 50 kHz
Transfer Function (ACC Mode) 25 mA/V
Input Range 0 to 10 V
Analog Monitor Outputs (Note: All outputs are single ended with respect to ground)
Ilim 0 to 250 mV = 0 to ±250 mA
ILD 0 to 250 mV = 0 to ±250 mA
IPD 0 to 2.0 V = 0 to 2.0 mA
Plim 0 to 2.5 V = 0to 2.5 mA
Physical Specifications
Dimensions (L x W x H) 5.0" x 2.5" x 0.8"
(127 mm x 63.5 mm x 20.3 mm)
Weight <1.5 lbs (0.68 kg)
Figure 2 IP250 Laser Diode Pin Codes. Caution: The E Style requires that the
Package Case must be floating with respect to the Power Supply Ground.

IP250-BV Blue Laser Diode Controller Chapter 3: Specifications
Page 10 10713-D02
Figure 3 Mechanical Drawing
Pin Description Pin Description
J1-1 +12 VDC In J5-1 TP Ground
J1-2 Common J5-2 ILIM Test Point (TP)
J1-3 -12 VDC In J5-3 ILIM Adjust
J2-1 LDA(+) or LDC(-) J5-4 IALARM
J2-2 Ground LDC(+) or LDA(-) J5-5 PLIM Test Point (TP)
J2-3 PD Cathode J5-6 PLIM Adjust
J2-4 PD Anode J5-7 Alarm
J3 0 – 10 VDC Modulate In J5-8 PMON Test Point (TP)
J4-1 Enable J5-9 P/I Adjust
J4-2 Ground J5-10 Enable
J4-3 Keylock J5-11 IMON Test Point (TP)
J4-4 Ground J5-12 2.5 Vref
J4-5 Inhibit JMP3-1 Ground
J4-6 Ground JMP3-2 PD Cathode
0.150"
(3.81 mm)
0.150"
(3.81 mm)
0.150"
(3.81 mm)
0.150"
(3.81 mm)
2.500"
(63.50 mm)
5.000"
(127.0 mm)
1.125"
(28.58 mm)
0.250"
(6.36 mm) 0.25" Hex Standoff, 4 Places
#4-40 Femail Thread
0.187" (4.75 mm) Deep

IP250-BV Blue Laser Diode Controller Chapter 4: Output Derating Curves
Rev F, October 24, 2017 Page 11
Chapter 4 Output Derating Curves
Since the IP250 is intended for use with blue or blue – violet laser diodes it is
optimized to operate with lasers that develop >5 V of load voltage (VOP). The power
dissipation of the main laser drive transistor is rated at 1.75 W. This rating is
maintained at full output current (250 mA) for any load voltage above 5 V when
powering the unit from a ±12 V power supply.
It is possible to operate with lasers with less than 5 V VOP, but the output current
must be derated to maintain a safe operating area for the drive transistor.
To determine the power dissipation of the drive transistor use the following formula:
ܲൌܫ
௢௨௧௣௨௧ሺܸ ௜௡ െܸ ை௉ሻ
Where:
Vin is the positive input voltage to the driver (typically 10 to 12 V).
VOP is the operating voltage of the laser diode.
Ioutput is the output current to the laser.
The following curve is provided for quick reference.
Figure 4 Derating Curve
0.00
0.05
0.10
0.15
0.20
0.25
0.30
12345678
Output Current
Laser Vop
Derating Curve (12 V Input)

IP250-BV Blue Laser Diode Controller Chapter 5: Regulatory
Page 12 10713-D02
Chapter 5 Regulatory
As required by the WEEE (Waste Electrical and Electronic Equipment Directive)
of the European Community and the corresponding national laws, Thorlabs offers
all end users in the EC the possibility to return “end of life” units without incurring
disposal charges.
This offer is valid for Thorlabs electrical and electronic equipment:
Sold after August 13, 2005
Marked correspondingly with the crossed out
“wheelie bin” logo (see right)
Sold to a company or institute within the EC
Currently owned by a company or institute
within the EC
Still complete, not disassembled and not
contaminated
As the WEEE directive applies to self-contained
operational electrical and electronic products, this end of
life take back service does not refer to other Thorlabs products, such as:
Pure OEM products, that means assemblies to be built into a unit by the
user (e.g. OEM laser driver cards)
Components
Mechanics and optics
Left over parts of units disassembled by the user (PCB’s, housings etc.).
If you wish to return a Thorlabs unit for waste recovery, please contact Thorlabs or
your nearest dealer for further information.
5.1. Waste Treatment is Your Own Responsibility
If you do not return an “end of life” unit to Thorlabs, you must hand it to a company
specialized in waste recovery. Do not dispose of the unit in a litter bin or at a public
waste disposal site.
5.2. Ecological Background
It is well known that WEEE pollutes the environment by releasing toxic products
during decomposition. The aim of the European RoHS directive is to reduce the
content of toxic substances in electronic products in the future.
The intent of the WEEE directive is to enforce the recycling of WEEE. A controlled
recycling of end of life products will thereby avoid negative impacts on the
environment.
Wheelie Bin Logo

,3%9%OXH/DVHU'LRGH&RQWUROOHU&KDSWHU7KRUODEV:RUOGZLGH&RQWDFWV
5HY)2FWREHU  Page 7
Chapter 6 Thorlabs Worldwide Contacts
For technical support or sales inquiries, please visit us at
www.thorlabs.com/contact for our most up-to-date contact information.
USA, Canada, and South America
Thorlabs, Inc.
sa[email protected]
[email protected]
Europe
Thorlabs GmbH
[email protected]
France
Thorlabs SAS
[email protected]
Japan
Thorlabs Japan, Inc.
[email protected]
UK and Ireland
Thorlabs Ltd.
[email protected]
[email protected]
Scandinavia
Thorlabs Sweden AB
[email protected]
Brazil
Thorlabs Vendas de Fotônicos Ltda.
[email protected]
China
Thorlabs China
[email protected]

www.thorlabs.com