HI
I use the DRV8302 to drive H-bridge for dc motor with a low side current resistor.
so i use only one current sense amplifier SP1 to high side of current resistor and SN1 to ground, pin REF has grounded to measure only one direction of current,
the inputs of second current amplifier was short to ground and out of S02 Left unconnected, pin 12/DC_CAL was short to ground.
The pins 34/SL_C, 36/SH_C, 38/BST_C, 35/GL_C, 37/GH_C left unconnected. Also unconnected pins are: 4/OCTW, 5/PWRGD, 55/EN_BUCK and pins 18-20-21--22, wich is the PWM inputs i dont use.
For my H-bridge i use mosfet CSD18533Q5A from TI with a 10 ohms gate resistor as my booster pack DRV8301.
In my first test i connect a DC motor of power about 25 to 50 watts 24V and everything works ok. So in my second test i connect a large motor of 240w 60v with Vbus 42V and was unable to drive the motor even at low speed, i thinking its problem of noise from big motor and change the R gate to make the switching time slower and i put R gate 100 ohms, the motor spin and i tray to push the drive in more hard test and i see from zero to 78% PWM motor start and stop with out problem, but from zero to more up the 78% PWM the motor dont spin and i thinking maybe activate OC _ADJ (pin 11), so i check my divider and my voltage on divider and i see my DVDD apply to divider a voltage of 4.6V instant of 3.3V.
My PCB is design with respect to ti booster back i have and example design from TI web side PVDD capacitor close to the pin with wide trace to power pad also for AVDD, DVDD and GVDD capacitors and AGND pin to power pad. The value of capacitors is the correct expect the GVDD wich is 4.7mf/25v.
The voltage on GVDD is 10.7V on AVDD is 6.6V and on DVDD is 4.6v (wich must 3.3) so what i do wrong ?
also i notice that when i turn on the drive the FAULT pin was high and when i enable the DRV8302 its go low but i can speed the motor.
