strange output of analog amplification stage
You really ought to link to the opamp datasheet in the question.

This shows the input offset voltage is typically +/-3mV. Multiply by your stage gain of -450, and you'll see the output offset voltage is about +/-1.5V, and with a single 3V supply rail, I hope you can see that will be a problem.

What you need to do is to reduce the stage gain at DC.

Incidentally you would probably be better to split the gain across both opamps, 22 in each, (well, 22 in the first, -22 in the second, if you keep the current topology) and AC couple from one to the other to eliminate accumulated offsets. Just turn U1 into a classic non-inverting amplifier (values shown give a gain of 23, reducing to 1 at DC) and reduce the gain in stage 2 to compensate.







simulate this circuit &ndash; Schematic created using CircuitLab

This will have another potential benefit : instead of one fast (unity gain) stage and one very low bandwidth stage (GBW/450 = 4kHz) both stages will have bandwidths of about 90kHz (GBW/23 or so)