AC/DC Analysis for Multistage Amplifier

0:00 - Intro
0:39 - DC Analysis: RE1
5:43 - DC Analysis: RE2
10:06 - Small Signal Parameters
13:11 - AC Analysis: Equivalent Model
18:09 - AC Analysis: Input/Output Resistance + Gain
22:52 - AC Analysis: Multistage Model
25:47 - AC Analysis: Final Gain Calculation
28:13 - Conclusion
Perform AC/DC Analysis for the Two-Stage BJT Amplifier.
Link to Analog Electronics playlist: • Analog Electronics
Hey everyone, I hope you learned and understood the Analog problem (Multistage Amplifier Analysis) a little better. Feel free to ask me any questions or give me suggestions in the comments below. If you enjoyed the video, please give it a thumbs up. Thanks!
Calculate the voltage gain, input resistance, and output resistance of the circuits provided below.
This video is part of a comprehensive walkthrough of the most common problems you will run into during Analog Electronics. This includes Single Transistor Amplifiers (both BJT and MOSFET), Multi-stage Amplifiers, Differential Amplifiers, Current Sources, Frequency Response of MOSFET-based single stage Amplifiers, and finally Feedback and Stability in MOSFET and BJT Amplifiers. I hope you find this playlist helpful!

Hello, would it be possible for you to give some sources that derive the expressions for Rin and Rout used in the video? Great content, thank you.

[@JJHanna]

Thanks! Here's a basic overview of some that I've found: engineering.purdue.edu/wcchew/ece255s18/ece%20255%20s18%20latex%20pdf%20files/ece255Lecture_16_Mar8_MOSFET_Basic_Config.pdf
I would also recommend looking at the Sedra Smith Microelectronics Textbook for all the other formulas, they cover it comprehensively.

[@user-lo3jd2ne7n]

i wish to ask how was Vt gotten

[@JJHanna]

Vt is thermal voltage. This constant is produced within the pn junction due to action of temperature. It equals kt/q, or Boltzmann's constant times temperature over charge of electron. At room temperature, this value is about 26 mV. This is assumed to be a constant and is typically provided for every problem. Does that answer your question?

[@ahmed_fouad1199]

Why in Rout1 we didn't count that it is vth2 is parallel to rc1 and ro

[@JJHanna]

I separated each stage so that I can take each external voltage gain into account during the final AC analysis gain calculation starting at 24:20.