Bjt
Operational Amplifier in LTSpice
Spent a few months teaching myself the internal layout of an OpAmp, then built one from scratch out of individual transistors in LTSpice.
- Learned and built every stage myself: differential pair, current mirrors, and a push-pull power stage
- Tested it by stepping the feedback resistor through four values and checking the gain against theory
- Measured gain matched the predicted Rf/Rin ratio almost exactly, even at ×1000