Other Parts Discussed in Thread: TIDA-00440, AMC1200,
I am designing a circuit similar to reference design TIDA-00440 - Leakage Current Measurement for Determining Insulation Resistance. I am using the combination of the INA333 and AMC1200 to detect the insulation resistance and obtain a 250mVpp differential signal with a output CM voltage of ~2.55V (VDD2 @ 5V). I need to translate the differential signal into single ended and feed it through a single ended ADC with FS 2.048V.
I was looking at using the INA333 to do the job. The manual mentions to have some kind of return path for the input bias current so the CM voltage does not float and change over time. Based on my simulations in TINA SPICE, the voltages looks good, but when I add any resistors to GND at the input of the INA333, it takes a very very long to complete and I do not think that it converges.
Any suggestions for what should be done with this type of setup for the input bias current or is there a better way to implement the DIFF to SINGLE stage?