We are measuring the voltage of a charger using the below circuit with the help of an ADC present in a microcontroller.

The value of charger voltage is required for some other applications. The value of charger voltage is used to calculate isolation resistance.

I tried to calculate the input from the output. I am getting an error of almost 2 V in my calculations.

We are using an AMC1350 and a TLV6001 in the signal chain.

Please see my circuit diagram and calculations below.

From the circuit diagram you can see that the input V2 is 58 V. I used the equation shown in the second image to calculate V2 from Vout.

I am getting a value of 56 V instead of 58 V. Where did I go wrong?

Regards

HARI