PICOLAS LDP-CWL 06-20 User Manual Download Page 12 | Manualshive

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PICOLAS LDP-CWL 06-20 User Manual Download Page 12

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Picture 4: Jumper positions for different modes

With Jumper J1 it is possible to set the working area of the LDP-CWL. Please set
the working area while the power supply and the input signal of the LDP-CWL are
turned off. Furthermore, please only set the working area as represented in the
upper pictures.

Important: Please refer to the position of the jumper as in the Picture 4, the

printing on the board may be different. However, it does not have any impact on
the functionality of the driver itself.

#5 and #6. Laser Diode Connection

Many elements and parasitic “stray” components may affect the performance of
the LDP-CWL. The stray inductance of the load connected to the driver is very
important. “Load” means not only the diode itself but also the packaging (bond
wires!) and leads between the driver and the diode. However, PicoLAS has no
influence on these parts. Thus, all measurements have been performed into a short
instead of a laser diode.
Refer to the PicoLAS Application notes “Impedance of Diodes” and “LD-
Connections” to get more information about parasitic elements and their effect on
the pulse shape (https://picolas.de/downloads/).

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Summary of Contents for LDP-CWL 06-20

Page 1: ...ser Manual LDP CWL 06 20 LDP CWL 12 20 Preliminary Manual PicoLAS GmbH Burgstr 2 52146 Würselen Germany Phone 49 0 2405 64594 60 Fax 49 0 2405 64594 61 E mail info picolas de Web www picolas de Rev 2102 ...

Page 2: ...8 Laser driver block diagram 9 Description of the connectors of the LDP CWL 06 20 LDP CWL 12 20 9 Modes and power dissipation 13 Frequency response 17 Trigger delay 18 Test load 19 Power supply 19 Crowbar 19 Current limiter 19 Mechanical dimensions 20 Absolute maximum ratings limits that can destroy the unit 20 ...

Page 3: ...3 ...

Page 4: ...gestion please do not hesitate to contact us Dos and Don ts Keep the cable connection between power supply and laser diode driver and the connection between driver and laser diode as short as possible to minimize the stray inductance Please set the laser diode driver only in the scheduled working area and only while the power supply is turned off Therefore please have a look at the section Descrip...

Page 5: ...he crowbar can be adjusted by the Potentiometer 1 The actual adjusted maximum output current limit can be measured at MP1 measurement point 1 An additional waveform generator might be needed which has to be connected to the input terminal There is no AWG arbitrary waveform generator included within the driver GND and LD are internally directly connected ...

Page 6: ...rator on input terminal no pulse before power supply enabled 0 V at current set pin 10 pin of the pin header Refer to all sections referencing input connector 2 5 Enable the power source Crowbar LED is on red 6 Adjust max current scaling of the crow bar Use the Set_Imax potentiometer 1 refer to the picture 1 above for scaling of the crowbar Scale 3 A V example 4 V at MP1 would limit the output cur...

Page 7: ... Turn the power supply for the Vcc back on Range of Vcc 15 V 48 V Minimum 10 V above compliance voltage 12 Feed a signal to the input terminal Make sure not to overload the laser diode Important Please refer to the position of the jumper as in the Picture 4 the printing on the board may be different However it does not have any impact on the functionality of the driver itself Required Laser Diode ...

Page 8: ...8 Laser Driver Block Diagram Picture 2 Block diagram of the laser driver Description of the Connectors of the LDP CWL 06 20 LDP CWL 12 20 Picture 3 Connectors of the laser driver ...

Page 9: ...ance 49 V 2 GND GND GND Connector Function Description 1 Power connector Vcc Screw terminal M3 2 Power connector GND for Vcc and input signal Screw terminal M3 3 Pin header See section Connection Pin header 4 Jumper J1 Set the working area See section Modes and Power Dissipation 5 Laser diode connector anode LD 6 Laser diode connector cathode LD ...

Page 10: ...ance output voltage 5 GND 6 N C 7 Disable reset crowbar connect to GND to disable reset 8 N C 9 Current monitor output 3 A V 5 example 4 V at current monitor output corresponds to 12 A at the output 10 Set output current 0 4 V A example 4 8 V reference voltage corresponds to 12 A at the output ...

Page 11: ...tput To achieve the correct scaling this pin has to be terminated with a high termination such as an oscilloscope and 1 MEG Ohm input impedance Due to the scaling amplifier and the quiescent current current flows through the output from up to 150 mA the current monitor output has an offset of approximately 50 mV 4 Connection Jumper J1 Jumper connection Working area of the LDP CWL XX 20 Short circu...

Page 12: ...e functionality of the driver itself 5 and 6 Laser Diode Connection Many elements and parasitic stray components may affect the performance of the LDP CWL The stray inductance of the load connected to the driver is very important Load means not only the diode itself but also the packaging bond wires and leads between the driver and the diode However PicoLAS has no influence on these parts Thus all...

Page 13: ...nual mode Man In every working area the driver achieves the best combination of a switching and a linear regulator This technique allows high energy consumption great linearity characteristics with a low output current ripple Mount the driver on an appropriate heat sink Please be aware that there might be hot surfaces be careful not to touch them Modes In the continuous wave mode CW it is possible...

Page 14: ...to its specifications e g bandwidth linearity output current The LDP CWL provides a step response with rise times more than 10 µs at an output current of 12 A in modulation mode To achieve a higher bandwidth and slew rate and to avoid distortion please use the Manual Mode Picture 5 Blue current monitor Purple output current set pin 10 of pin header 3 ...

Page 15: ... of your system you have to read the power dissipation at the desired output current Afterwards this value has to be multiplied with the duty cycle Example Rectangle wave with a duty cycle of 20 Desired output current 5 A Desired compliance voltage 10 V Resulting Pd from the graph is 8 W 1A Power dissipation 8 W 1 A 5 A 0 2 8 W The manual mode Man is appropriate for pulsed signals such square wave...

Page 16: ... transistor of the linear regulator to achieve higher bandwidths for waveforms such as pulsed or rectangle waves DC link voltage has to be less than Vcc 10 V and more than 5 5 V Vcompliance to achieve higher bandwidths Frequency Response The following graph demonstrates the 3dB bandwidth for increasing output current values of the LDP CWL 12 20 in manual modus The following measurement results are...

Page 17: ...17 Trigger Delay The delay between the triggering signal and the load current is typically td 2 2 µs Picture 6 Trigger delay ...

Page 18: ...pin 10 pin of the pin header crowbar has to be toggled set low and then high 7 pin of the pin header For inherent protection the LDP CWL automatically shuts down itself if an error occurs Firstly if temperature rises above 80 C secondly if no load is connected and thirdly if the output current is higher than the set current This condition is latched To re enable the LDP CW the ENABLE pin must be t...

Page 19: ...stroy the unit Vcc limit The input voltage is in the range of 15 V 48 V but at least 10 V above compliance voltage Output current 6 0 A LDP CWL 06 20 12 0 A LDP CWL 12 20 Operating temperature range 0 C 55 C Operating temperature range for best performance 10 C 35 C storage temperature range 20 C 70 C ...

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