Hi Chris,
Connecting the C to VM instead of ground provides several benefits. Without going into all the details:
There is less leakage in the capacitor when the charge pump is off. The voltage difference between VCP and VM is less.
The voltage rating of the capacitor is lower. This is not noticeable in the DRV8833, but can be seen in the DRV8880. The capacitor rating is 16V instead of 63 to 100 when running at 45V.
Connecting the C to VM instead of ground provides several benefits. Without going into all the details:
There is less leakage in the capacitor when the charge pump is off. The voltage difference between VCP and VM is less.
The voltage rating of the capacitor is lower. This is not noticeable in the DRV8833, but can be seen in the DRV8880. The capacitor rating is 16V instead of 63 to 100 when running at 45V.