DRV10983: The PWM speed control motor does not spin and only turns at 100% Duty

Cherry Zhou

Part Number: DRV10983

Hi team,

Here's an issue from the customer may need your help:

When the DRV10983 PWM control motor speed is applied, the fan does not start when 1% to 2% of the output input PWM controls the speed. Can only spin up at 100% Duty. Could you help check this case? Thanks.

Best Regards,

Cherry

over 3 years ago

0 Vishnu Balaraj over 3 years ago

TI__Mastermind 24415 points

Hi Cherry,

Thanks for posting your question in MD forum. Can you make sure the speed input mode is set to PWM mode? Also, after you issue the PWM speed command, can you read the speed command and speed command buffer register from the device and share it with us?

Regards,

Vishnu

0 Cherry Zhou over 3 years ago in reply to Vishnu Balaraj

TI__Mastermind 22235 points

Hi Vishnu,

Thanks for your help.

Vishnu Balaraj said:
Can you make sure the speed input mode is set to PWM mode?

Yes, after removing ISD, everything works properly.

While this device is required to turn on the ISD, there will be a problem with turning on the ISD start-up sense BEMF. They've tried to change the inductance to resistance for verifying.

The PWM is generated by the signal generator, and they did not read the register value. Once the rotor is moved by hand, it spins normally.

Thanks and regards,

Cherry

0 Vishnu Balaraj over 3 years ago in reply to Cherry Zhou

TI__Mastermind 24415 points

Hi Cherry,

Can you refer to the below E2E which talks about Motor startup failure when ISD is enabled?

https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/1003334/faq-drv10987-motor-startup-failure-when-isd-is-enabled

Regards,

Vishnu

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DRV10983: The PWM speed control motor does not spin and only turns at 100% Duty