Hello user5994067,
There are a couple of issues with the circuit configuration that are causing incorrect operating conditions to be established. First, there aren't return paths to ground for the OPA2197 input bias currents. And second, the input generator is floating. There is no dc common-mode voltage (Vcm) level from which the inputs can be referenced. Therefore, because of these two issues the inputs attain whatever dc they happen to come to affecting the levels that the input and/or output can swing before clipping occurs.
I took your circuit and added both input bias current return resistors, and a +3 V Vcm source. A level midway between 0 V and the +6 V supply. The differential voltage gain of the circuit is 30 V/V with the resistors you selected. The amplifier circuit can accept an input voltage up to about 180 mVpk at the input before the output begins to clip. Using the gain of 30 V/V, times +/-180 mVpk, the output swing extends form +600 mV to +5.4 V. The swing limits are set in the simulation model so the output will clip once the limits are exceeded.
I have included my TINA circuit for your examination:
A point regarding your circuit, the 10k resistors in series with the OPA197 non-inverting inputs are not needed and add additional thermal noise to the circuit. Additionally, the 4.7 nF capacitor across the generator isn't doing anything unless the generator has a non-zero impedance. If the generator has some resistance the capacitor will from a low-pass filter with that resistance.
Regards, Thomas
Precision Amplifiers Applications Engineering
