Consider the ac equivalent circuit shown in Figure P4.18. Assume \(r_{o}=\infty\) for the transistor. The small-signal voltage gain is \(A_{v}=-8\) for the case when \(R_{S}=1 \mathrm{k} \Omega\).

(a) When \(R_{S}\) is shorted \(\left(R_{S}=0\right)\), the magnitude of the voltage gain doubles. Assuming the small-signal transistor parameters do not change, what are the values of \(g_{m}\) and \(R_{D}\) ?

(b) A new value of \(R_{S}\) is inserted into the circuit and the voltage gain becomes \(A_{v}=-10\). Using the results of part (a), determine the value of \(R_{S}\).

Transcribed Image Text:

Figure P4.18 ww Rs www Rp OV