DRV11873: DRV11873 Input PWM frequency limit

Annie Liu

Part Number: DRV11873

Hi Team,

Customer uses TI's DRV11873 chip as a brushless motor driver IC. The input PWM frequency required by the chip specification is 7~100Khz.

The PWM input is 110Khz, and the motor speed can be adjusted by adjusting the duty cycle of the input PWM. The input frequency of 110Khz exceeds the requirements of the chip specification. Can it be accepted? Is there any risk in applying to the product?

Thanks.

over 6 years ago

0 Sanmesh Udhayakumar over 6 years ago

TI__Expert 6065 points

100kHz is the max specced PWM input frequency. Thus we cannot guarantee proper motor operation at 110kHz operation.

0 Annie Liu over 6 years ago in reply to Sanmesh Udhayakumar

TI__Genius 10295 points

Customer would like to know what will happen when motor operation over 110kHz operation? Does this cause THD or EMC? Or any other questions?

0 Sanmesh Udhayakumar over 6 years ago in reply to Annie Liu

TI__Expert 6065 points

We cannot clearly say. I would guess the duty cycle wouldn't be guaranteed to be read correctly. One of the reasons for a max pwm frequency is that it is limited by the sampling of the duty cycle rate.

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DRV11873: DRV11873 Input PWM frequency limit