laser driver 3 amp 20 v 5ns rise time

[dougmc]

I need halp in circuit design for a laser driver to control a laser max rated 3 amp 20v, the drive would be a
square wave less than 5ns rise time,vary in width 200-1000ns.
I can use a Phillips PM5139 generator for the drive..
https://courses.engr.illinois.edu/ece445/documents/manuals/PM5139_manual.pdf

Thanks in advance
doug

 

[chuckey]

To maintain a 5ns rise time right through to your laser will be difficult. What capacitive load does it present? I think you will need your power amplifier wired directly to the laser and feed it via a piece of 50 ohm coaxial from the preamplifier.
Frank

 

[dougmc]

Thank you for the reply.l will try to get the capacitive loading specification. iC-Haus has one very close but not enough voltage.They recommended a cascade transistor to follow but had no design or recommendation.

 

[doraemon]

Hello!

I know the iC-Haus products quite well. But what kind of laser are you going to use?
Is it really a 20V diode? It sounds very high. As for the driver, I think you are referring to iC-HG,
which can drive 9A in pulse mode and go to sub ns rise time with the proper diode.
I think you should start by explaining everything and at least put a link to your diode.
(or your laser).

Dora.

 

[HTA]

Hello dougmc,

you can achieve with the iC-HG laser current switch rise times below 1ns, if you have a proper designed layout and interconnection with low inductance ( see: https://www.ichaus.de/wp4_fastlaserdriver ). The maximum driver voltage needs to be less than 12V. Laser diodes are in some cases switched on with higher voltages to get faster rise times, however the with a current switch and low impedance in the signal path this is not needed.

Enjoy your design work!