Lect.26: BJT amplifiers(1)

Lect. 26: BJT amplifiersAmplifier equivalent circuit modelVinR inA voR outV outCE r o1v in-g m1 r o1 v inr π1r π2CBβr o2Cascode open-circuit voltage gainv outg m2r o2v in2v = g r vout m2 o2 in2rv = ( −g r v )π 2in2 m1 o1inrπ2+ ro1r∴ v = g r ( −g r v )π 2out m2 o2 m1 o1inrπ2+ ro1rg r ( − g r v )π 2m2 o2 m1 o1inro1Assuming g = g , r = rvA = −βg rm1 m2 o1 o2outvo m1 o1vinElectronic Circuits 1High-Speed Circuits and Systems Laboratory