AD7280A Vdrive

I am designing a 4 cell LiFePO4 battery monitor using AD7280A and a PIC microprocessor running at 3.3v. The 3.3v supply is connected to Vdrive. As soon as I set PD to 3.3v to activate the AD7280, the Vdrive pin back-feeds about 4.6v into the PIC power supply (the PIC is only using a few mA). Is this expected behaviour? I have replaced the AD7280A in case I damaged it, but this behaviour on the new chip is the same. The rest of the circuitry around the AD7280 is as per the data sheet.

Thanks

Nick.

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    •  Analog Employees 
    on Dec 22, 2020 9:15 AM 2 months ago

    Hi, 

    Apologies for missing this item. I am not sure if it still relevant to you that this question will be answered, However, we are clearing up some open items in our community and ensure that any query is located on its proper community as others who have similar concern or issues may still find this useful.

    I am moving this thread to the Power By Linear Community. Someone here may be able to help you.

    Thanks,

    Jellenie

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  • 0
    •  Analog Employees 
    on Dec 22, 2020 9:15 AM 2 months ago

    Hi, 

    Apologies for missing this item. I am not sure if it still relevant to you that this question will be answered, However, we are clearing up some open items in our community and ensure that any query is located on its proper community as others who have similar concern or issues may still find this useful.

    I am moving this thread to the Power By Linear Community. Someone here may be able to help you.

    Thanks,

    Jellenie

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