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DRV8870: DRV8870

Hoa Nguyen4
Prodigy 70 points
Part Number: DRV8870

Hi,

   I am using DSPIC33EP512 MCU to control the PWM output of DRV8870.  When set the duty cycle to any level between 1-100% to PWM control IN1 or IN2 of DRV8870, the output of Out1 or Out2 is not matching with the PWM i set.  Ex: If i set it 100%, the output is around 28%.  If I only control IN1 or IN2 as On or Off, the Out1 and Out2 voltage are as expected.

I am using CCS C compiler IDE version 5.064, and the control.  With the same control i tested to PWM control a mosfet gate, and the duty cycle come out as expected.  

DRV8870 Circuit.pdf

  • 0
    TI__Guru** 114905 points
    Hi Hoa,

    Can you provide a scope capture of the two outputs? This will help determine what could be causing this.

    What is the motor specifications? R/L
    If the current is too high when starting, the overcurrent may be causing a problem. Look for the outputs to disable for approximately 3ms
    If the current is less than the overcurrent, overtemperature could be causing the problem.