• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 29 subscribers
  • Views 89 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.

DRV8210P: DRV8210P

Sasanka Thewarapperuma
Prodigy 20 points
Part Number: DRV8210P

Hello All, 

Any guidance on this is appreciated. 

I have used the H-bridge driver in the following configuration: 

I use this to drive a latching valve with a 20ms pulse.  Upon valve closing there seems to be a reverse emf on the VDD_SYS_3.3V in the form of kick back from the inductive load. 

It was my impression this would be freewheeled with the built in diodes but its not the case. 

Is the combination of VCC and VM potentially causing this issue OR I may be doing something thats not ideal when it comes to the driving signals IN1,IN2, nSLEEP?

Any thoughts are appreciated. 

Thanks again,

Sasanka. 

  • 0
    TI__Expert 6750 points

    Hi Sasanka,

    Thank you for your question.

    It is likely to be a combination of your switching frequency and supply voltage. 

    I would suggest increasing the PWM switching frequency. Slow switching can make EMF kickback worse with inductive loads. 

    If possible, it may help to increase the supply voltage to mitigate EMF kickback to the supply.

    Another suggestion would be to implement a flyback diode across the load to safely dissipate the inductive current during switching periods. 

    Best,

    David

  • 0 in reply to David Medis
    Prodigy 20 points

    Hi David, 

    Thanks for your reply.  We have a very infrequently switched valve with an output pulse of 20ms which we have utilized this part to drive. 

    This happens twice in every 134 seconds as a part of a treatment cycle. 

    If you mean the switching supply frequency which we feed the VCC and VM with, its likely to be in light load scenario loading up the bulk capacitance to support the valve load. So frequency may be variable and not in a PWM mode to have a fixed switching frequency. 

    Flyback diode idea is a reasonable idea to try out. Will update on this. 

    Cheers,
    Sasanka.