I'm working on a design using the DRV8353HMRTAT. I originally designed for the DRV8353FHRTAR, but had to populate with the HM instead due to availability. I believe they are the same except for safety rating and temperature range. I'm having trouble getting the part to behave the way I think it should. A PWM input produces no output and the nFAULT line appears to be low all the time, even during and after I pulse ENABLE low for 30us.
I am only using 2 of the three outputs. MODE is set to 3x PWM (47k to GND). INHA and INHB are the PWM inputs, INLA and INLB are pulled high through a 10k resistor, INHC is floating, and INLC is tied to GND. I see ~5V on DVDD output and ~16V on VGLS output. VM is 16V for now, although we also need it to work at 54V.
I originally didn't have a pull-up on nFAULT, but I added one and it's still low all the time. Continuity check shows it is not shorted to GND.
GAIN is set to 10V/V, drive current to 100/200mA, and VDS set to 0.4V. The FETs I'm driving are FDMS8090 dual packages. Gate resistors 22 ohm.
Any ideas on what I might be doing wrong?
Thanks,
Mitcham
