Consider the common emitter amplifier shown below with the following circuit parameters: β = 100, gm = 0.3861 A/V, r0 = ∞ rp = 259 Ω, Rs = 1 kΩ, RB = 93 kΩ, RC = 250 Ω, RL = 1 kW, C1 = ∞ and C2 = 4.7mF. The resistance seen by the source Vs is

258 Ω

1258 Ω

93 kΩ

∞

Correct Answer: 1258 Ω

Explanation:

Z_s = R_s + (R_B || Br_s)

r_c = 2.475 = 1.258 kV

Z s = R s + (R B || B r s ) r c = 2.475 = 1.258 kV

Question

Consider the common emitter amplifier shown below with the following circuit parameters: β = 100, gm = 0.3861 A/V, r0 = ∞ rp = 259 Ω, Rs = 1 kΩ, RB = 93 kΩ, RC = 250 Ω, RL = 1 kW, C1 = ∞ and C2 = 4.7mF. The resistance seen by the source Vs is

Accepted Answer

Z_s = R_s + (R_B || Br_s)

r_c = 2.475 = 1.258 kV