• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 30 subscribers
  • Views 88 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DRV8837: OUT pin absolute maximum voltage

Nicolas Divel
Prodigy 10 points
Part Number: DRV8837
Other Parts Discussed in Thread: DRV8220

Tool/software:

Hello,

I am working on a project using the DRV8837 motor driver. We have a regulated voltage supply (Vm) of 10.5V. During braking, we have observed that the OUT1 and OUT2 pins can experience voltage spikes between 12V and 13V for approximately 20µs.

We would like to know if these voltage spikes pose a risk of stress or damage to the DRV8837. Specifically, we are concerned about the maximum voltage tolerance of the OUT1 and OUT2 pins.

Could you please provide information on:

  • The absolute maximum voltage ratings for the OUT1 and OUT2 pins.
  • The device's tolerance for short-duration voltage spikes on OUT1 and OUT2 above Vm.
  • Any recommendations for mitigating these voltage spikes if they are a concern.

Thank you for your assistance.

Sincerely,

Nicolas

  • 0
    TI__Mastermind 23361 points

    Hey Nicolas,

    12V is the absolute max on the pin, so anything beyond that is definitely a risk.  We can't guarantee behavior beyond 12V - it might be fine for a small project, but if you build thousands of boards it might cause an issue in some over time.  

    If this is just a personal project then you can probably just leave it as is. However if you want to play it safe you can upgrade to DRV8220 which is Pin to Pin compatible and 20V abs max.  Upgrading to DRV8220 is my recommendation - it would be easy and eliminate all risk.  (If not you should look at DRV8212P, it is a P2P drop in replacement for DRV8837 with a much higher current limit).  

    What is your bulk capacitance value?  Maybe a larger bulk capacitor can help with the spike.  See Bulk Capacitor Sizing for DC Motor Drive Applications

    Also see How to Reduce VM Pumping here:  https://www.ti.com/document-viewer/lit/html/SSZTCH8#:~:text=Reducing%20Voltage%20Pumping You could add a TVS diode, but that could be expensive and large space.  

    The easiest way to reduce the spike would be to slow down your rate of braking - instead of a hard stop, PWM ramp the INx change over 50ms or similar.  So instead of setting IN1 from 1 to 0 instantly, PWM it from 100% to 0% over 50ms. 

    Best,

    Jacob