Dear Team,

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

 

The circuits shown do not include any connections to the charger circuit. Nor do the circuits shown indicate any degree of isolation relative to the charger circuit.
Thus it is not possible to even guess at any answer, as none of the required information is presented.

 

The circuits shown do not include any connections to the charger circuit. Nor do the circuits shown indicate any degree of isolation relative to the charger circuit.
Thus it is not possible to even guess at any answer, as none of the required information is presented.

This is just a simulation model.Charger is represented as V2 AMC 1350 is an isolation amplifier

 

This is just a simulation model.Charger is represented as V2 AMC 1350 is an isolation amplifier

The input to the isolation amplifier is not isolated. So other voltages can be present. Any connection to a "common" prevents isolation.