gm = IC/VT
Av = -gm*(RC||RL||rc) (bypassed emitter)
Av = -RC/(RE+re) (unbypassed emitter)
Rin = R1||R2||Rπ (bypassed emitter)
Rin = R1||R2||[(RE+re)*ß] (unbypassed emitter)
Rout = rc||RC||RL
Rout ≈ RC
Rπ = ß/gm
re = 1/gm
rc = VA/IC
Av = voltage gain
ß = transistor current gain
gm = transconductance
IC = collector current
RC = collector resistor
rc = internal collector resistance
RE = emitter resistor
re = internal emitter resistance
Rin = input resistance
RL = load resistor
Rout = output resistance
Rπ = internal resistance from base to emitter
Rs = source resistance
VA = Early voltage
VT = (kT)/q ≈ 30 mV
Frequency response
High-pass filter
FC1 = 1/(2π(RS+Rin)C1)
FC2 = 1/(2π((re+(Rth/ß))||RE)C2)
FC3 = 1/(2π(Rout+RL)C3)
Low-pass filter (Miller-capacitance)
FH1 = 1/(2π*Rout*CoutM)
FH2 = 1/(2π(Rth||Rπ)(Cbe+CinM))
Rth = R1||R2||RS
CinM = Cbc(|Av|+1)
CoutM = Cbc(|Av|+1)/|Av|
Cbc = base to collector capacitance
Cbe = base to emitter capacitance
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