Common mode servo (S1605810) was modified for the new IMC control configuration.
-
Slow path roll-off filter: changed the cut-off frequency from 100 kHz to 30 kHz
C261->1.5n -
Fast path main filter: changed to band path filter between 2k Hz to 50 kHz
C279->0.47u
R187->2k
R179->0
C290->2.2n
R184->0
R188->2k -
Slow path generic filter: gain stage of 0.1 for cross-over frequency optimization
R138->NL
R13->0
R141->1k
The transfer function was measured. The servo configuration is as follows:
- Injected excitation signal from IN1 and measured at FAST and SLOW out.
- IN1GAIN and FASTGAIN is 0 dB
- COMCOMP was on
- All other filters are off.
All of the TF was consistent with the calculated one. I attached Fast path one. Blue curve is from IN1 to Fast OUT, red curve is from IN1 to SLOW OUT, and orange is from EXCB(2) to Fast OUT.
You can see the phase delay due to the electronics is 62 deg at 1MHz.
