I am facing issues using the DRV8316 in 3xPWM mode to drive a BLDC motor.
The overcurrent current protection (OCP) always triggers in one of the three channels and put the driver into fault condition. This event happens at start-up a lot but also when the motor is spinning already fast. Also, OVC error comes very often with overtemperature error but I am not able to tell which one triggers first.
To eliminate any motor control problem I did tests with a single resistor to dissipate power between 2 driver channels. You can see below the resulting current of PWM injected into the resistor. The peak value of the current is ~ 8 A.
I know the chip is limited to 8A peak but the peaks on the scopes are very short (<5µs) resulting in an average DC input current much lower. I have tried this experiment with 9V and 18V DC input supply but the result is the same.
- With the following setup, is it normal that the chip goes into fault ?
- What is the point to set OCP_LVL register to 16A or 24A if the OCP protection is actually triggered by such peaks ?
Thank you for your help !
