Hi, I am experimenting with motor phase-out current sensing instead of the standard low-side shunt. I am running into an issue however with noise on the current sense amp output due to the large common-mode voltage swings of the switch nodes. I am working on ways to address this, but I have a question about one avenue I may try. In the existing design, the phase voltage sensing goes through a quite low low-pass filter (in my case, around 330Hz), and the result is a very smooth output free of any noise. I would like to try the same on the current sense signals (this would not be possible with low-side shunt since it only carries current when low FET is on, but should be possible with phase-out sensing as it always carries phase current). The problem is that the LPF will introduce a phase delay dependent on the electrical frequency of the motor. My question is, where does the code adjust for the phase delay of the phase voltage feedback due to the LPF (I can't see it anywhere in the code, so I am guessing it's in the FAST block)? Is there a way I can make phase adjustments of the phase currents in the same way using the existing built-in functions? The LPF would also affect the magnitude of the signal but this is much simpler to correct.
Using F28069.
Thanks,
Ken.
