Continue from last post, to solve the problem, we need to acknowledge that the buffer circuit is in fact a feedback loop
To identify which components belong to with block – refer to the blog
Let’s modify the schematic to perform bode plot analysis
1. Ground non-inverting input – since op-amp input is already high impedance – any voltage source with series resistance is pretty much behaving just like a pure voltage source – for DC voltage source, it is always a AC ground.
2. Place large inductor, infinite AC coupling capacitor and AC source, configure the AC source as below:
3. Choose AC analysis:
4. Your schematic should becomes:
5. After simulation, you get
6. But, how to interpret the plot?