I’m using UCC27201A gate drivers in a BLDC motor controller design. The prototype board is hand-wired. When I increase the motor supply voltage to 30-40V with 25% PWM duty cycle, a random driver fails. Typically, the driver shorts the 12V supply and the low side output shorts to ground. An ohmmeter measures about 20ohms for the low side short, but the chip only shorts 12V in-circuit. Sometimes the driver doesn’t short the 12V and the low side is open or there’s no output. In this case, the high side output continues to work. The FETs have failed a few times, though none since I added an 18V zener to the 12V supply. I’ve seen the 12V supply rise quickly when a driver fails. The 12V supply has also dropped when there’s driver failure. I’m guessing the failures are due to poor grounding and long wires, unavoidable with the prototype, but I’d like to rule out any design errors that would cause the PCB (in layout) to fail. Partial schematic with scope captures attached.
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