Problem:
1. For the follower circuit in Figure, let transistor Q1:
have β=50 and transistor Q2:
have β=100, and neglect the effect of ro. Use VBE =0.7 V.
a) Find the dc emitter currents of Q1 and Q2:
Also, find the dc voltages VB1 and VB2.
(b) If a load resistance RL =1 kΩ is connected to the output terminal, find the voltage gain from the base to the emitter of Q2:
vo/vb2, and find the input resistance Rib2 looking into the base of Q2:
(Hint: Consider Q2:as an emitter follower fed by a voltage vb2 at its base.)
(c) Replacing Q2:with its input resistance Rib2 found in (b),analyze the circuit of emitter follower Q1:to determine its input resistance Rin , and the gain from its base to its emitter, ve1/vb1
(d) If the circuit is fed with a source having a 100-kΩ resistance, find the transmission to the base of Q1:vb1/vsig.
(e) Find the overall voltage gain vo/vsig.