I work on my master thesis and use the ADUM4135 guys to create a 3-phase bridge for BLDC motor. Unfortunatelly two upper drivers are continuously in fault state. When I open lower transistors to charge up the bootstrap capacitors and power up the upper drivers, the READY pins associated to the upper drivers are set active, but the FAULT pins are active too. I thought it is cause of the desaturation detection, so I short the caps between the desat. pins and VSS2 pins (see attached figure), disable the desat. detection. Well this didn't help.
Strange thing is that only two upper drivers are wierd, the last one is ok and works fine. By the way, I also tried replace those two upper drivers with brand new but nothing. The problematic guys are the first two on the left in the schematic.
Can anyone help me please?
thanks a lot for replay ADI!