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Consider a CE circuit, where trans-conductance is 50mΩ-1, diffusion capacitance is 100 pF, transition capacitance is 3 pF. IB = 20μA. Given base emitter dynamic resistance, rbe = 1000 Ω, input VI is 20*sin(107t). What is the short circuit current gain?

Consider a CE circuit, where trans-conductance is 50mΩ-1, diffusion capacitance is 100 pF, transition capacitance is 3 pF. IB = 20μA. Given base emitter dynamic resistance, rbe = 1000 Ω, input VI is 20*sin(107t). What is the short circuit current gain? Correct Answer 35

AI = IL/IB IL = -gmVb’e Vb’e = Ib rb’e/(1+jωCrb’e) C = CD + CT = 103pF Vb’e = 20μ.1k/(1+j.107.103.10-12.1000) AI = IL/IB = 50m.1k/(1+j.107.103.10-12.1000) AI = 35 (approx).

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