Hello,
I am going to use the sigma-delta modulator to sample the feedback current. I wonder is there any dynamic model for it (combined with the digital CIC filter) like transfer functions that can describe the dynamic behavior of this kind of modulator , e.g., how much phase delay it will introduce to the control loop at middle and high frequency range. I have known the transfer function of the CIC filter from the datasheet and some reference design, but it seems not adequate, and it is also a bit difficult to take a multi-rate analysis. Therefore, I hope some experts can give me more information about using and analyzing the sigma-delta modulator, especially from the view of control system design.
Any help would be appreciated.
Thanks,
Sirius