PICOLAS LDP-VRM 025-100 CA User manual

User
Manual
PicoLAS GmbH
Burgstr. 2
52146 Würselen
Germany
P one: [phone]
Fax: [phone]
E-mail: [e-mail]
Web:
www.picolas.de
Rev. 1909
LDP
-
VRM 025
-
100 CA

2
Table of Contents
How to use t e Manual..............................................................................................3
Absolut maximum Ratings ........................................................................................3
Dos an Don’ts ............................................................................................................3
Product Overview..................................................................................................... 4
How to get started.....................................................................................................5
Required Laser Diode Pinout .................................................................................... 6
Power Driver Block Diagram .................................................................................... 6
Description of t e Connectors.................................................................................. 6
Power Supply and absolute maximum Ratings......................................................... 6
Input .........................................................................................................................7
Jumper ......................................................................................................................7
Current Monitor ........................................................................................................7
Bias and scaling Potentiometers ...............................................................................7
Test Load...................................................................................................................7
Power Dissipation......................................................................................................7
Mec anical Dimensions.............................................................................................7

3
How to use the Manual
Remark:
Please read all instructions before powering up t e device.
Please see section “Power Dissipation” for more details about t ermal power
losses during operation.
Please pay attention to all safety warnings. If you ave any doubt or suggestion,
please do not esitate to contact us!
Absolute maximum Ratings ( estroying limits)
All input pins may not exceed t e voltage range below zero (GND) and beyond
VCC
VCC Limit: see table in section “Power Supply (#3)”
Peak output current: 2.5 A
Operating temperature range: 0 °C .. +60 °C
Best performance operating temperature range: +10 °C .. +35 °C
Storage temperature range: -20 °C .. +70 °C
Dos an Don’ts
Never ground any output connector.
Never use any grounded probes at t e output.
Do not connect your oscilloscope to t e output!
Driver and t e probe will immediately be destroyed!
Keep t e connecting cables between power supply and driver as well as between
driver and laser diode as s ort as possible.
Please be aware that there might be hot surfaces. Be careful not to
touch them.

4

5
How to get starte
T e basic settings (scaling and BIAS current etc.) can be adjusted by
potentiometer.
Bias set a dc output current up to 1.6 A wit out connecting input signal.
You need an additional waveform generator w ic as to be connected to t e
input terminal. T ere is no AWG included wit in t e driver!
Step What to do heck
1 Solder a dummy diode between LD+ and
LD-. Alternatively make a s ort circuit
t ere.
See section “Test Load”
2 Connect GND, VCC to power connector
(power source disabled).
VCC 24 V
3 Connect waveform generator to input
terminal (no pulse before enabling power
supply).
See all sections discussing input
(connector #2).
4 Enable t e power source.
5 Adjust scaling and bias. See potentiometer for scaling a
bias.
6 Feed a signal on t e input terminal. For
example 1 kHz sine wave wit 1 V
amplitude.
Make sure not to overload t e
laser diode or t e driver.
Range of input signal 0 V .. 5 V.
7 Monitor t e current output. T e current monitor measures a
signal comparable wit t e input
signal. Use an oscilloscope wit a
1 MEG o m termination. Scale 165
mV/A.
8 Disable t e input signal and turn off t e
power source.
Remove t e test diode or bypass and
assemble t e final laser diode.
9 Turn t e power supply for t e VCC on
again.
VCC 24 V.
10 Feed a signal to t e input terminal. Make sure not to overload t e
laser diode!
Require Laser Dio e Pinout
T e LDP-VRM 025-100 CA is designed for a direct connection to almost all kinds of laser
diodes. T e laser diode can be connected directly by a screw terminal.

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Power Driver Block Diagram
Description of the Connectors
Power Supply an absolute maximum Ratings
Pin of conn. #3 Allowed range Best performance Destroying limit
1 VCC (laser supply) 24 V .. 26 V 30 V
2 (GND) GND GND
3 (Input terminal) 0 V .. 5 V - + 5.3 V

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Input for Current Setpoint
T e analog setpoint signal is provided via t is connector. T e output current follows t e
input signal proportionally wit in t e driver’s limitations (bandwidt , max. current, rise
time).
Jumper
T e analog input can be switc ed to an inverted digital input.
Set t e jumper left to activate t e inverted digital input.
Bias an scaling Potentiometers
T e bias potentiometer sets a DC output current up to 1.6 A w ic is added to t e input
signal. Turn it rig t to increase t e bias current.
T e scaling potentiometer varies wit t e scaling of t e input signal.
Turn it rig t to increase t e scale from 0 A / V to 0.5 A / V.
Test Loa
For t e first test an appropriate test load may be assembled instead of t e laser diode.
T is test load can eit er be a s ort circuit or a Sc ottky diode like t e ES3C. Please
connect t e test load only between anode and cat ode (LD+ and LD-) and prevent
s orts to any ot er part of t e circuit.
Power Dissipation
T e control of t e driver reduces t e power dissipation automatically to a minimum.
T e driver as to be cooled and allows a maximum power dissipation of 4.5 W.
Mechanical Dimensions
T e following dimensions are in millimetres (mm).
widt 40 // lengt 145 // eig t 25