Other Parts Discussed in Thread: TL031,
Dear TI E2E community,
We are implementing a 3 phase voltage measuring circuit using the AMC1100 isolation amplifier. Our DAC unit requires a bipolar input of +-10V range, so I am using the TL031 operational amplifier in differential mode to get rid of the common mode voltage set by the AMC1100 and to amplify the signal up to the DAC full range.
The main problem is that this design is not as precise as we require, and the voltage output suffers from high common mode voltage (200mV or more), gain error (slightly reduced) and distortion of the waveform when zero crossing. We tried using high precision resistors (0.1% tolerance) and although the output improved, the problem still persists, particularly at low input signals.
Are we doing something wrong? In case no, is there any other way to achieve this configuration with improved accuracy?
Many thanks in advance and Kind Regards,