Week 04
Op-Amp Internal Structure
I study differential stages, feedback, filters, and output stages as one connected signal path.
What I connect in this unit
The differential input stage converts input difference to current, the gain stage builds large open-loop gain, and the output buffer supplies load current. A bias network establishes operating currents and DC levels throughout the three stages.
Concept map
- Differential input stage
- Gain stage
- Output buffer
- Bias network
Technical anchor
A stage view gives A0 ≈ gm,input·Rout,input × gm,gain·Rout,gain × Av,buffer, with output-buffer voltage gain usually near one.
How I review it
On an internal block diagram, mark the path that amplifies input offset, the high-impedance node forming the dominant pole, and the buffer path carrying load current.
Connection to the full course
Unit 4 of 12. Unit numbers follow concept dependencies rather than the historical lecture calendar.