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DRV8243-Q1: Don't want to use nSleep in HW variant

Kei Kuwahara
Expert 7630 points
Part Number: DRV8243-Q1
Other Parts Discussed in Thread: SN74LV123A

Tool/software:

Hello team,

My customer is considering to use HW variant of DRV8243-Q1.

However, they don't want to use Sleep function. (Device always active)

On the datasheet, 9.2 Typical Application says that it is mandatory to issue a reset pulse for nSleep, even if nSleep is not needed.

However, on Figure 7-4, nSleep is kept HIGH from the beginning.

Can customer keep the nSleep HIGH when start up?

Best Regards,
Kei Kuwahara

  • +1
    TI__Mastermind 44445 points

    Hello Kuwahara-san,

    Yes, for the DRV8243-Q1 hardware variant as described in the datasheet pin control is mandatory even if sleep function may not be needed in the application. The purpose is to provide the required reset pulse tRESET as indicated in the t4 of Figure 7-4. Else the device will not start up correctly. 

    Kei Kuwahara said:
    Can customer keep the nSleep HIGH when start up?

    But they have to provide the reset pulse as shown at time t4. Else the device will not work correctly. Thank you.

    Regards, Murugavel 

  • 0 in reply to Murugavel4637
    TI__Expert 7630 points

    Hello Murugavel-san,

    Thank you for your detailed answer.

    I suppose the reset pulse (tRESET) for nSLEEP should be 20us to 40us. (From what I see on the parameter table below)

    My customer is claiming that 20us - 40us pulse is difficult to generate using GPIO of the MCU.

    How are other customers generating this reset pulse?
    Is there any good solution for generating precise pulse?
    (For example, use SN74LV123A, etc.)

    Best Regards,
    Kei Kuwahara

  • +1 in reply to Kei Kuwahara
    TI__Mastermind 44445 points

    Hello Kuwahara-san,

    Kei Kuwahara said:
    I suppose the reset pulse (tRESET) for nSLEEP should be 20us to 40us. (From what I see on the parameter table below)

    Yes this is correct. 

    Kei Kuwahara said:

    My customer is claiming that 20us - 40us pulse is difficult to generate using GPIO of the MCU.

    How are other customers generating this reset pulse?
    Is there any good solution for generating precise pulse?

    As far as I know customers have implemented with GPIO of the MCU. If it is difficult to get this pulse from their MCU, any Schmidt trigger single gate buffer device and RC can be used for a pulse generator. It does not have to be very precise. 20 to 40 us is large enough window. In MCU GPIO with a small delay loop with NOP instruction could do the trick. 

    Regards, Murugavel