I have a new board design and I'm trying to debug why the DRV8880 immediately issues a fault. If I toggle the enable pin and trigger on the fault pin I can see it being 3.3V for less than 3us. I've measured all the pin voltages and I don't see any reason for the part to go into fault but every time I power up or toggle the enable pin it immediately goes into fault. Perhaps I have something wrong in my design that I'm not seeing? I've attached the schematic and the spec on the motor being used.
Here's what I measure on each pin
| Name | Pin # | Voltage (V) |
| CPL | 1 | 0.133 |
| CPH | 2 | 23.4 |
| VCP | 3 | 35.7 |
| VM | 4 | 23.9 |
| AOUT1 | 5 | 0 |
| AOUT2 | 7 | 0 |
| AISEN | 6 | 0 |
| BOUT2 | 8 | 0 |
| BOUT1 | 10 | 0 |
| BISEN | 9 | 0 |
| ATE | 13 | 3.3 |
| VREF | 14 | 1.05 |
| V3P3 | 15 | 3.3 |
| TOFF | 16 | 0 |
| nSLEEP | 17 | 3.3 |
| nFAULT | 18 | 0 |
| DECAY1 | 19 | 0 |
| DECAY2 | 20 | 0 |
| ENABLE | 21 | 3.3 |
| DIR | 22 | 0 |
| STEP | 23 | 0 |
| M1 | 24 | 0 |
| M0 | 25 | 0 |
| TRQ1 | 26 | 0 |
| TRQ0 | 27 | 0 |
Thanks in Advance,
George
