This is the circuit I am working on.
I am using this instrumental amplifier AD623 with a gain of 100 using a 1k resistor between pin 1 and 8.
(https://www.analog.com/media/en/technical-documentation/data-sheets/AD623.pdf)
Based on this, my input voltage can swing from -0.05v to 0.05v.
When input voltage is 0.05v the simulation works without problems as I post on the image.
The problem I am having is that when input voltage is -0.05v I get error on simulation and I think is because I exceed specs of the input common voltage of the ic.
I need to understand how can I get correct output voltage based on the input voltage I mention.
(If input voltage is -0.05v output can be any value <5v without problem in this circuit design)
Best Answer
Your gain is set to 101, so you're expecting an output voltage of about 5V. If you look at the datasheet:
The output can only approach 5V for a very narrow range of common mode voltage.
If you give it a -5V rail it will be able to handle a much wider range of inputs for output near the positive rail, as shown in Fig. 32 & 33.