There are a few documents describing the AFE and PI control loop. What seems to be missing in detail is the way the error is calculated and fed into the PI controller. What is documented in PGA411-Q1 Resolver Sensor Interface.pdf does not work when implemented verbatim.
I would like to model the tracking loop in Simulink so I can pass through real speed/angle data to access the angle error and stability. My questions are:
1) In the Analogue Application Journal; System Modeling in Matlab Simulink for PLL-based resolver-to-digital converters, a model is described of the PGA411-Q1. Is this model available for download?
2) Could you please explain how the analogue error signal gets demodulated and how this becomes a 16bit representation of error?
3) Although the tracking loop runs at a high update rate, am I right in thinking the update of the error is based on the excitation frequency?