I am testing a circuit that seems to be exhibiting strange behavior vs simulation.
I expect a DC gain of ~1.4x, which the simulation shows.
This is the circuit in question. The final amplifier is a placeholder for the ADAQ7988's internal ADC driver.
The problem I am experiencing is that even though the LT6017 and ADAQ driver are powered by dual supplies, the low-end performance of the circuit is not representative of the gains expected. At 20 mV I am only seeing a gain of 1.1x and not seeing the full gain of 1.4x until about 2V.
Perhaps I need to use a different amplifier to better model the ADC driver?
Even though it is dual-railed, this behavior seems to be more like I would expect from a single supply.
Anyone else experience this?