What's the ADP3634's internal driver's resistance, Rdson?
Some typical tests in the past with the AD3634, gave the following results:
Rdson measured ( from test data)
NDMOS Rdson: 0.78ohm
PDMOS Rdson: 0.96ohm
The Rdson is independent of the power supply,VDD. Remember there are also
bonding and package resistances/inductances to be considered.