Hi team,
This is a failure case of DRV8847S. I compared the impedance of pin to GND of each pin, which is shown in following table.
A crucial phenomenon is that there is a burn mark on the top of package around VM pin. And when I try to separate the chip from board, the VM pin fell. So there must be some electric damage to the VM pin when DRV8847S are operating. I found that the Cin 10uF was far from DRV8847S. Will this cause the damage of DRV8847S?
| Pin to GND | Normal chip | Failure Chip |
| 1 | 319.64k | Open |
| 2 | 1.9135M | 1.35M |
| 3 | 1.6086M | 1.36M |
| 4 | 1.9109M | 1.34M |
| 5 | 1.9073M | 16 |
| 6 | 1.6091M | 15 |
| 7 | 1.9155M | 10 |
| 8 | Open | 60 |
| 9 | 199k | 217.04k |
| 10 | 197k | 218k |
| 11 | 198k | 216.72k |
| 12 | Open | Broken |
| 13 | 。 | 。 |
| 14 | unstable | Open |
| 15 | 198k | 214.19k |
| 16 | 200k | 216.26k |
Nison
