Hello.
I am experiencing a problem with DRV8402. I am using the driver in parallel configuration with cycle-by-cycle current limiting mode. Schematic is designed according to application note.
There is also 1mF capacitor between PVDD and GND, which is not shown in the picture. The motor is rated 2.2ohm, 240uH. Overcurrent protection is set to 10.6A with 27kohm resistor.
The setup works ok when I feed only one PWM channel and the other is kept low all the time. In this scenario motor is allowed to coast.
Yellow and blue is PWM A and B, purple and green is voltage on the motor windings.
The problem occurs when I try to incorporate dynamic braking. The driver shuts down issuing 0 on the FAULT pin.
Overtemperature pin stays high. The problem occurs regardless of PWM frequency.
I understand that in CBC current limiting mode PWM width should be reduced to prevent further current increase and not to allow overcurrent shut-down.
The second thing. How is that possible that at the output I get only 12V amplitude with 24V supply on PVDD?
Best regards,
Mariusz