Troubleshooting Multistage Amplifier Design

Thread Starter


Joined Feb 28, 2018
Hello all,
I am designing a four stage amplifier with the goal of producing a gain of 1000 on the output. I believe I solved all of the resistors and capacitors correctly and on paper I should be seeing the gain I need but on SPICE my output is not what I need it to be. Based on the voltage probes I placed, the error seems to be on the third stage but I don't see the issue. I would love feedback (pun unintended) on my design and to see if anyone spots an error in my circuit.
multistagespice.PNG multistagespiceoutput.PNG


Joined Feb 8, 2018
I'll get you started

Look at each stage individually and tell us in a few words what it you expect it to do. What voltage gain do you expect? Why?
Briefly say what each of the components (or "sets" of components) is expected to do.
You have as many free instruments as you want in simulation. Why are you looking at so few signals?

It is generally very useful to name the nets rather than allowing the simulator to pick the names for you. In this particular case the names aren't too bad, but some could be better. Input is more meaningful than V(R1:1)