The ISO5451DWR is mysteriously shutdown while driving IGBT power transistor. Runs fine at low voltage motor voltage of 100VDC and low current. But as the motor voltage increase towards 200VDC the driver stops operating. After failure the part has the following voltages on these pins. FLTn and RDY is high. IN+ is high. 15VDC on VCC2. Any ideas as to why this is failing will be appreciated.