DRV8835 Seems to be Dead - Killed by noise?

I purchased two of the DRV8835 Dual Motor Driver (pololu.com/product/1117). Everything seemed to be working for a while but then both motors stopped running. After checking all connections, verifying supply voltages, and double checking the PWM output, I swapped out the DRV8835 with the second one I purchased. It ran for a few seconds and then stopped working just like the first.

I’m using a PIC18F2455 to generate basic PWM signals. The motor driver is powered by a 6V NiMH battery to VIN and then the microcontroller and VIN of the motor driver is powered by the same battery after a 5V regulator. The motors are connected directly to the motor driver. Here is a picture of the setup: i.imgur.com/PzSRiQq.jpg

In doing some research, it looks like the motors might be producing more noise than the motor driver can handle and I think I’ve fried both DRV8835s. Could someone verify this? I’m also trying to figure out what the best next step should be. Should I buy a few more DRV8835s and try to add in a cap filter on the motor? Should I look at a different motor driver that can handle this motor better? The DRV8833 (pololu.com/product/713) also looked like a good option.

Thank you for your help!


Hello.

I am sorry you are having problems driving your motors. It is possible that the noise from those motors damaged your motor driver. From our experience, the DRV8835 does not handle driving those motors well (you can read more about this here). We recommend switching to the DRV8833 dual motor driver, which is similar in size and seems to be robust when used with those motors. If you email us at support@pololu.com with your order information and reference this post, we might be able to help you out with a small discount towards replacements.

- Jeremy

Thanks Jeremy! I emailed support and will put in an order for a few DRV8833 drivers soon. Are there any filters I should add to help ensure I don’t damage the DRV8833? I see this wiring diagram here (pololu.com/file/download/dr … e_id=0J534) but I’m not finding anything about recommended filters. I just want to be sure before I kill a few more boards. :slight_smile:

Although it might help, you should not need any additional filtering for those motors when driving them with the DRV8833. When we tested the DRV8833 with Tamiya motors, we did not have filtering capacitors across the motor leads. If you do want to reduce motor noise, you might find this application note helpful.

- Jeremy