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DRV8811: UVLO Minimum value

Yusuke Mukuno
Expert 7395 points
Part Number: DRV8811

Hi Expert, 

VM UVLO for rising is 6.7V(typ) and 8.0V(max) from datasheet.

Could you please let me know the VM UVLO value for falling? Is it same value?

Also, please let me know the minimum value. (There is no problem with reference values that are not guaranteed.)

Thanks

Muk

  • 0
    TI__Guru 55565 points

    Muk-san,

    Please see following section in the datasheet.

    7.3.5.3 Undervoltage Lockout (UVLO) If at any time the voltage on the VM or VCC pins falls below the VM or VCC undervoltage lockout threshold voltage, all circuitry in the device will be disabled, and the indexer will be reset to the home state. Operation will resume when VM and VCC both rise above their UVLO thresholds.

    It should also be noted that there is ~300mV of hysteresis between tripping protection on/off so that there is no oscillation between on state and off state.  

    Regards,

    Ryan

  • 0 in reply to Ryan Kehr
    TI__Expert 7395 points

    Ryan-san,

    Thank you for your answer.

    I understand, VM falling UVLO is 6.4V(typ) and 7.7V(max) . Is it correct?

    Also, Could you please give me your comment for minimum value?

    Thanks

    Muk

  • 0 in reply to Yusuke Mukuno
    TI__Guru 55565 points

    Muk-san,

    It is a US holiday today.  I will respond by tomorrow.

    Regards,

    Ryan

  • 0 in reply to Ryan Kehr
    TI__Guru 55565 points

    Muk-san,

    Datasheet is confusing.  The "rising" comment should be deleted.

    Basically, device is guaranteed operational at >8V.  Once device is operational and voltage begins to fall below 8V, UVLO occurs typically at 6.7V.

    Once any UVLO trip happens, voltage has to change >300mV for device to begin operating again.  And UVLO trip can occur as early as 8V, but unlikely based on typical value of 6.7V.  

    Regards,

    Ryan