Cascode Amplifiers (17-Transistors)

All about cascode amplifiers for the bipolar transistor. Derivation of the gain using the small signal model and by inspection. Explanation of the high frequency performance. Everything is derived and explained from first principles. How does the cascode amplifier avoid the Miller effect?
Aaron Danner is a professor in the Department of Electrical and Computer Engineering at the National University of Singapore.
danner.group
Video filmed and edited with help of CIT, NUS.

[@qwaqwa1960]

You're generally quite precise, so...hope to see connection dots in future schematics...!

[@grzesiek1x]

Finally I understood that parasitic capacitance! And also i understood finally why HF transistors have ultra low capacitance at base - collector! My BFR93A has something like 0.5 pF !!! So it is like 16 times less than 2n2222 !!!

[@manitoba-op4jx]

now you see why cascodes were a thing, lots of tubes have grid-plate capacitances in the hundreds of pF

[@SUPADIEGAZO]

In the case of the common emitter amplifier, rpi should be in series with (Beta+1)x(RE//RE1)

[@anoimo9013]

what happens with the miller capacitance when the gain is positive?. Isn't it a problem then? Does the miller capacitance behaves as an inductor?

[@JaenEngineering]

Nothing happens to it, but more importantly, it isn't amplified like it is with an inverting amplifier.

[@user-de8rr9nw4t]

Can you introduce the super regenerative receiver?

[@adideljanin8436]

19:20 Is this error? Emitter resistance is (re||1k+5)xBeta and not (re+5)xBeta. Am i right? Anyway great video.

[@adanner]

You're right but here re is nearly the same numerically as re||1k since re is small, so I just neglected the ||1k.

[@stevenbliss989]

The frequency response is NOT "a little bit better", it is HUGELY better!
...get your facts straight man :) :) :)