Hello,
While testing two interleaved TPS50601-SP (dual phase) converters at 125degC, I experienced a failure of both devices. The test conditions were 5Vin, 0.8Vout at a total load current of 15 amps. After the failure, the output slowly increases when I apply input voltage (I assume leakage from bootstrap capacitor) with no load. Once I apply even the smallest of loads to the output the voltage collapses and input current draw remains low, 30 mA. I performed ohm/diode checks on both devices and did not detect a short circuit on either the top or bottom FET. I also confirmed on the master device that the SYNC out was working (500kHz). The BOOT output was also registering 4.2volts for both devices and the soft start and comp pins were reading 2.2 volts. So, it would appear that the FETs are not shorted but for some reason they are not being driven on. No visible damage seen on the die itself. Any idea what could be the cause of this particular failure?
Thank you.
