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DRV8303 Min PWM output frequency

masahiko shimizu
Guru 11235 points
Other Parts Discussed in Thread: DRV8303

Hi,

Could you let me know minimum PWM output frequency, please?
I know that max frequency is 200kHz from datasheet.

Customer wants to use at 7Hz PWM input(very slow).
and sets motor speed by changing duty of 7Hz.

DRV8303 has bootstrap capacitor.
I am concerned about becoming output of high side weaker.

If it is difficult to answer for less information, could you advice me in case of EVM?

Best regards,
Shimizu

  • 0
    TI__Mastermind 26065 points

    Hi Shimizu,

    Ideally the device can work at 100% duty cycle which means long time high side gate voltage sustain. So 7 Hz should be fine. Please make sure there is no external GS path even high resistance path.

    But I think we don't have to go such low PWM frequency, we can alway has constant high PWM frequency but with low frequency modulation for the 3 or 6 PWM inputs. Such as 1% or 99% to replace the constant LOW and HIGH control.

    Best regards,

  • 0 in reply to Wilson Zuo
    Guru 11235 points
    Hi Wilson,

    Thank you for your advice.
    It is very helpful for me.

    Best regards,
    Shimizu