Hi Rick,
Yes, the power pad is connected to ground.
Please find the relevant schematics below:
Below is the capture of nFault spikes (Yellow waveform) and the Gate drive outputs PWM_AL (Blue waveform) . THe PWM inputs are 32kHz square waves. DRV is configured in 3 PWM mode, current limit mode.
We have zoomed in on the captures of nFault w.r.t GVDD. PVDD and DVDD.
1) PVDD (Yellow waveform, after AC coupling) w.r.t nFault (Blue waveform)
The spikes seen are of a few hundred millivolts, which we believe should not be the cause of an undervoltage lockout.
2) DVDD (Blue) w.r.t nFault (Yellow)
There is a drop of around 1 V.
3) GVDD w.r.t nFault
Please provide your opinions.
Regards.