LTC6115 amplifier A1 supply voltage question

I am designing a power supply and for the display I would like to use the LTC6115 as it seems to have the functionality that I need to monitor both voltage and current except that the A1 amplifier looks to be totally dependent on the same supply for Vsense in the datasheet. My DC power supply variable range is from 0V to 60V. There is no way amplifier A1 could operate at 0V. Given the typical minimum operation voltage for the current sense amp (A1) section at V+ should be no less that 5 volts for Supply1, could the V+ be connected to a separate fixed supply? 

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    •  Analog Employees 
    on Jun 24, 2020 2:01 AM 5 months ago

    Hi ote,

    Unfortunately, you can't operate A1 from a different supply than what is being measured. This part is meant to be used as high-side current sense, where input common mode is very close to the supply. It can't also  sense current at 0V supply.

    If you needs a wide input voltage sense range, we recommend to check out the LTC2945 or LTC2946. Those are power and current monitor products that can sense voltages from 0V-80V in the case of LTC2945, and 0V-100V for LTC2946.

    I hope this helps.

    Best regards,