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DRV8889-Q1: Lowest voltage to ensure shut down

Frank QIN
Expert 8950 points
Part Number: DRV8889-Q1

Tool/software:

Hi Team,

According to the datasheet, the minimum operation voltage of DRV8889-Q1 is 4.5V.

While we want to confirm what is the voltage level to ensure the device is shut down? For example, can I say the DRV8889 can absolutely shut down when VM is lower than 2.7V?

The reason for asking this is we are working on configure the power up/down logic. If we can ensure a voltage level that the device can absolutely shut down, we can just set the power down voltage level simply below this.

Thanks

Best,

Frank

  • 0
    TI__Mastermind 45465 points

    Hi Frank,

    Please refer to the below shown section of the datasheet. Around 3.9 V is needed for the device to have an internal POR (no SPI operation possible). Between 3.9 V and ~ 4.35 V it will be in the under voltage zone, charge pump will be disabled and device will be disabled.

    Between 0 and 3.9 V the device will be in an indeterminate state meaning the digital circuit may have random states because no POR happened. Having a supply voltage > 0 and < 3.9 V will not be considered powered down although the device will be inactive. So to turn off the device for extended periods please have supply voltage to 0. Having 3.9 V or 2.7 V to VM will not damage the device. It is not best practice. May be I misunderstood your question.

    Frank QIN said:
    While we want to confirm what is the voltage level to ensure the device is shut down? For example, can I say the DRV8889 can absolutely shut down when VM is lower than 2.7V?

    Technically speaking when the VM voltage goes below UVLO falling threshold device outputs will shutdown, charge pump will be shutdown but SPI will be operational until the voltage falls below VRST.

    See also section 7.3.11.1 VM Undervoltage Lockout (UVLO) in the datasheet. I hope this helps with your decision. Thank you.

    Regards, Murugavel