DRV8353F: DRV8353F dying when motor channels shorted together

Part Number: DRV8353F

Tool/software:

DRV8353F chip, functional motor controller design. Follows EVB nearly 1:1 on the DRV circuit.  We did however add gate Zenors to clamp any voltages over 15v. SH to Gate and VSS to Gate for high and low side respectively.  Without these, high powered motors WOULD pop the driver(actually the same fault and power draw as described below).  We are using a boost regulator to power VM.  At the time of this test VDRAIN was only 18v. VM was 12v.  NO load on the motor channels.  Test was a direct short from A to B channel (C was not active). The drivers are immediately dying on channel short.

TOLL mosfets, 105ns, approx 1.2mohm RDson(eg very high powered). Expect full load to run at 150 amps continuous/300amps peak, have tested to 60amp up to this point.

Drive Control Register 0x420

Gate Drive HS Register 0x333

Gate Drive LS Register 0x033 on one test and 0x133 on second test.

OCP Control Register 0x067

CSA Control 0x200

FAULT and GDUV flags after driver dies. Power on reset does not clear. Driver pulls ~100ma after failure.

If you could point out my mistake in settings and/or recommendation on what to look at in our design.

Based on the EVB I was expecting this to be a nothing test. Shorts across channel, shorts to GND, shorts to PWR/VDRAIN.

Any help would be appreciated.

  • Hello,

    The first thing I can recommend to look into is playing with the VDS_LVL and OCP_DEG settings. Lower VDS threshold and Lower deglitch time should help the driver detect the phase to phase short condition earlier and shut down in time to prevent damage.

    These settings are pretty system-based so fine tuning to find the right should be done here. Ex: finding a VDS level that correctly catches the short condition in time, WITHOUT triggering during normal operation.

    Of course, if the device fails this test it will likely be unusable going forward, as you see ~100mA draw on startup which is indicative of damage due to the high current scenario.

    If you are unable to find a working combination here please let me know and we can keep looking for a solution.

    Thanks,

    Joseph