Question 7.SP.21: Find an expression for the voltage gain Av = vp/vg of the ba......

Schaum’s Outline of Electronic Devices and Circuits [1089587]

Find an expression for the voltage gain $A_v = v_p/v_g$ of the basic triode amplifier of Fig. 4-12, using an ac equivalent circuit.

4.12

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The equivalent circuit of Fig. 7-9(b) is applicable if $R_L$ is connected from P to K. Then, by voltage division in the plate circuit,

v_{p} = {\frac{R_{L}}{R_{L}  +  r_{p}}}\left(-\mu v_{g}\right) \qquad \text{so} \qquad A_{v} = {\frac{v_{p}}{v_{g}}} = {\frac{-\mu R_{L}}{R_{L}  +  r_{p}}}

7.9

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