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Entry  Mon Jan 24 18:13:20 2011, Zach, Electronics, GYRO, PDH servo basic_design.png
    Reply  Tue Jan 25 00:05:57 2011, Koji, Electronics, GYRO, PDH servo 
       Reply  Tue Jan 25 01:30:01 2011, Zach, Electronics, GYRO, PDH servo PDH2.pdf
          Reply  Tue Jan 25 01:39:00 2011, Koji, Electronics, GYRO, PDH servo 
             Reply  Tue Jan 25 02:09:16 2011, Zach, Electronics, GYRO, PDH servo 
                Reply  Tue Jan 25 02:18:17 2011, Koji, Electronics, GYRO, PDH servo 
                   Reply  Wed Jan 26 01:20:10 2011, Zach, Electronics, GYRO, PDH servo PDH2.pdf
                      Reply  Wed Jan 26 06:20:03 2011, Koji, Electronics, GYRO, PDH servo 
                         Reply  Wed Jan 26 12:42:36 2011, Zach, Electronics, GYRO, PDH servo 
                            Reply  Wed Jan 26 18:10:37 2011, rana, Electronics, GYRO, PDH servo 
                               Reply  Wed Jan 26 19:47:42 2011, Zach, Electronics, GYRO, PDH servo PDH2.pdf
                                  Reply  Wed Jan 26 20:01:31 2011, Zach, Electronics, GYRO, PDH servo 
Message ID: 1274     Entry time: Wed Jan 26 18:10:37 2011     In reply to: 1272     Reply to this: 1275
Author: rana 
Type: Electronics 
Category: GYRO 
Subject: PDH servo 

This seems too hokey to me. Just use the AD829 and the switching techniques that are in the Sigg electronics. Using this relay/LF crap will leave us with a lot of phase lag. The board should have less than 10 deg. of phase lag at 300 kHz.

1) For the regulators, you should use bigger caps in parallel with the little caps. Big means > 50 uF.

2) Since this is quasi generic, you ought to have more pads around the input opamp and some of the others. Look at the layout of the generic stages in the Sigg MC board.

3) For the RF, we don't want to put the PD signal through a noisy phase shifter. The LO signal shoudl be the one getting phase shifted.

 

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