DRV8711: Coil measurement

Marvin Gasis Arcangel

Genius 9725 points

Part Number: DRV8711

Hi Team,

I need help with the question below:

If A1HS and A2LS are enabled and the MOSFETs are energized what should be measured across the Coil A.

This part is used as a driver for a stepper motor with the VM is set to 24 VDC

Thank you in advance

Regards,

Marvin

over 1 year ago

0 Pablo Armet over 1 year ago

TI__Mastermind 37683 points

Marvin,

The voltage across the coil will be slightly lower than 24V (subtract the voltage drop across the FETs RDSon). However, this is true if the control input is DC (100% duty cycle). If PWM is switching, the average output voltage will depend on the duty cycle. For example, switching at 50% duty cycle will result on an average voltage of ~12V (1/2 of 24V).

Regards,

Pablo Armet

0 Marvin Gasis Arcangel over 1 year ago in reply to Pablo Armet

TI__Genius 9725 points

Hi Pablo,

Thanks. I would like to know what do I need to do to run at 100% duty cycle?

Regards,

Marvin

0 Pablo Armet over 1 year ago in reply to Marvin Gasis Arcangel

TI__Mastermind 37683 points

Marvin,

To run at 100% duty cycle, set one of the inputs to 0V and the other tied to 3.3V or another external logic supply less than 5v.

Regards,

Pablo Armet

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DRV8711: Coil measurement