Circuit analysis estimation techniques

[ItsMike]

Hi everyone,
I'm currently taking a "Analog Linear Circuit" course and during the course we have used the open/short-circuit time constants technique to estimate bandwidth of amplifiers.

This technique seems pretty useful on real circuits where you just want to estimate the dominant pole.

Are there any more of these techniques ? Or any tricks/mental shortcuts or whatever for quick estimates of circuit analysis ?

[w2aew]

Quick and dirty estimation of gain of a common emitter amplifier without emitter degeneration is simply equal to the voltage drop across the collector resistor divided by vt (26mV).

[rbola35618]

Here are two examples in how to use the open time constant to calculate the bandwidth.

Robert

[LvW]

Are there any more of these techniques ? Or any tricks/mental shortcuts or whatever for quick estimates of circuit analysis ?

The gain of a common emitter stage with Re feedback (emitter degeneration) can be estimated as G=-Rc/Re.