DRV8844: Drive 4 solenoids, input 100Khz PWM to EN pin to reduce current

Yue TANG

Part Number: DRV8844

Hi experts,

My customer used DRV8844 to drive solenoids, but in their board they will use 16 pcs DRV8844, each DRV8844 need to drive 4 channels solenoids. every channel will consume 0.8A current. if all these solenoids work, the total current will be close to 50A. So, they came out a solution, to input PWM on EN pin , which will lead to Intermittent current flow through the solenoids, then dramatically reduce the total current. and they have to keep a small current flow through the solenoids periodically due to maintain a certain torque. Also I was told the PWM signal will be 100Khz. please kindly give your suggestion is this a feasible solution? welcome your idea for this case?

BTW, they will power DRV884 with +-24V [ dual power rails], each output pin of DRV8844 will connect to a solenoids, then to ground.

over 4 years ago

0 Wang5577 over 4 years ago

TI__Guru 56650 points

Yue,

PWM signal on EN pin to reduce the solenoid current consume should work with 100kHz PWM frequency.

I thought PWM signal on INx before. After check the ENx and INx pin delay spec, I agree PWM signal on ENx pin should work.

Please check the solenoid. Is it 24V or 48V rating? When you apply +24V to VM and -24V to VNEG, the solenoid will get 48V. Also, we may need to think about the current balancing between +24V and -24V output when they are in series.

0 Yue TANG over 4 years ago in reply to Wang5577

TI__Expert 8485 points

Thanks for the reply. I've feedback to customer, please wait for my further question.

0 Wang5577 over 4 years ago in reply to Yue TANG

TI__Guru 56650 points

Sure, you can reopen this post by posting your further questions.

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DRV8844: Drive 4 solenoids, input 100Khz PWM to EN pin to reduce current