I'm working on a project that requires at least 40 dB gain at 40kHz. I originally used one non-inverting amp using 10k and 1k resistors for a gain of 11. Using cascading rules for linear systems, I cascaded another non-inverting amp of the same gain.
Below is the simulation and circuit that I am trying to implement.
I implement this system using the LMC662 Dual Op-Amp Datasheet: https://www.ti.com/lit/ds/symlink/lmc662.pdf?ts=1602456193412&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FLMC662
When I run each amplifier separately using Analog Discovery 2 and waveforms, I get the expected frequency responses as shown below.
But when I cascade it, I get a funky response like this:
Why does this not work as expected?
Note: The High Pass Filter is only being used to simulated a receiver system whos frequency response mimics and band pass