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TAS5805M: Disable DVDD and keep PVDD 19V in power down application

Gary Teng
Genius 5840 points
Part Number: TAS5805M

Tool/software:

Hi Sir,

 Customer want to disable TAS5808M's DVDD and keep PVDD on their design when their system is in power down condition.

1. Is there any issue if only provide PVDD and shut down DVDD on TAS5808M? IC will be damaged or not?

2. When power is back to DVDD, any reset / command need to be send for TAS5805M?

Thanks and regards,

Gary Teng

  • 0
    TI__Genius 10305 points

    Hey Gary, 

    DVDD and PVDD provide different power needs and both must be provided. One doesn't replace the other.

    DVDD would need to be biased for IC functionality and PVDD would need to be biased to provide headroom for the output signal. 

    When power is back to DVDD, the IC would act like it's being powered on for the first time. I would recommend re-writing the i2c commands to the IC again to continue functionality. Follow the start-up sequence in section 7.5.3.1. 

    Regards,

    Ore.

  • 0 in reply to Ore Ogundana
    Genius 5840 points

    Hi Ore,

     Thanks. And is there any damage issue on IC if customer just provide PVDD?

    Regards,

    Gary

  • 0
    TI__Genius 17990 points

    Hi Gary,

    This should be fine. In power sequencing for this device it does not matter if DVDD or PVDD are powered up first. Just ensure PDN is low when powering down and up. When powering down PDN should be low for at least 6 ms before removing the supply.

    Regards,
    Sydney Northcutt 

  • 0 in reply to Sydney Northcutt
    Genius 5840 points

    Hi Sydney,

     About PDN control, if there's no DVDD, PDN function is still workable?

    Regards,

    Gary

  • 0 in reply to Gary Teng
    TI__Genius 10305 points

    Hey Gary, 

    PDN is for the shutdown procedure and the device would have to be in normal operation mode for this feature to activate. Normal operation mode requires both DVDD and PVDD to be biased and like Sydney pointed out, the order in which they are powered on doesn't matter. 

    Regards,

    Ore.