The DRV8301 (used in Odrive v3.5-48v, amongst others) has an errata on the datasheet:
The DRV8301 gate drivers may not correctly power up if a voltage greater than 8.5 V is present on any
SH_X
pin when EN_GATE is brought logic high (device enabled) afterPVDD1
power is applied.
The SH_X
pin is directly connected to the motor terminals.
For ODrive, that seems to mean the gate driver won’t work properly if the motor is already spinning when the odrive is reset or powered up. That presents problems for things like wind turbines, hydro generators, and anything else where the motor is probably always spinning.
The symptoms I’ve seen are that the low side overcurrent fault flags (eg. FETLA_OC
) get set whenever this is the case, although sometimes with a delay of a few milliseconds.
Is there any known workaround? Does the chip work properly if you just disable overcurrent protection, or is this flagging up a real fault because the mosfet gate isn’t being driven completely during powerup?