As per last reply, we have checked the VM & DVDD nets on scope.
We find out very strange behaviour of DVDD pin.
Our observation as below
#1 : At start up VM rise pattern looks normal. And then the voltage on the VM appears as per supplied. The observed noise and ripple might be due to our power supply who is sourcing 24V
#2 : However, the DVDD net is rising upto 6.60V at power up. Even after power up its having deterministic frequency component @1.12Khz with max amplitude going upto 6.80.
While testing this DVDD is only connected to VDS & IDRIVE.
#3 : The C69 cap of 1UF MLCC is correctly soldered ( Refer original question for schematic & layout )
#4 : The same problem has been noticed on all 5 boards we assembled.
#5 : Even after ABA swap, issue is still same.
#6 : We directly installed brand new DRV in place of damaged to rule out nay pin damage assumption but no success
Note : The DVDD line seems very much sensitive. While connecting scope to the net with test pin, one of boards DVDD failed. Means it was initially appearing 4.42V but suddenly become zero. And did not reappeared even after all the attempts.
The behaviour of DVDD ( 4.42 V ) is same irrespective of EN pin status. Just applying 24VDC starts showing 4.42V on DVDD
