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Entry  Wed Mar 30 14:12:10 2011, Alastair, Electronics, GYRO, Trans PD 100MHz_PD.pngPD_trans.fil.tar
    Reply  Thu Mar 31 00:33:36 2011, Frank, Electronics, GYRO, Trans PD 
       Reply  Thu Mar 31 11:25:43 2011, Alastair, Electronics, GYRO, Trans PD PD_trans.fil.tar
Message ID: 1365     Entry time: Wed Mar 30 14:12:10 2011     Reply to this: 1367
Author: Alastair 
Type: Electronics 
Category: GYRO 
Subject: Trans PD 

I'm in the middle of stuffing the first Trans_PD at the moment.  I'm using the following values for the resonant notches:

  • AC coupling
    • L6=6.8uH
  • 100MHz notch
    • C2=22pF
    • C4=9pF(1.5-15pF tunable)
    • L3=82nH
  • 200MHz notch
    • C10=6.3pF(1.5-15pF tunable)
    • L2=100uH

You can compare these values to Zach's 33MHz diodes in this post.  The lower inductance of L3 gives a lower transimpedance and I've set the gain of the opamp to 2.

I have some concerns that we don't want to much gain for these PDs.  A total transimpedance of 30dB V/A means that 20mW of laser power becomes about 7dBm at the output of the PD.  If we're using a level 13 mixer then that seems about right.  If we want to increase the power at all then we will need to attenuate the output of the PD.

LISO file is attached

Attachment 1: 100MHz_PD.png  17 kB  | Hide | Hide all
100MHz_PD.png
Attachment 2: PD_trans.fil.tar  2 kB  Uploaded Thu Mar 31 12:30:18 2011
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