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Chapter 1 Basic Electronic Concepts and SignalsExample 1.6For the current amplifier of Figure 1.24, derive an expression for the overall current gainA i = i load ⁄ i s.i inA isc i ini outi sR sR inR outi loadV loadR loadSolution:Using the current division expression we obtainFigure 1.24. Current amplifier for Example 1.6Also,i loadi in =R s-------------------iR s + R sinR out= -----------------------------AR out + R isc i inload(1.28)(1.29)Substitution of (1.28) into (1.29) yieldsori load =R outR S-----------------------------AR out + R isc--------------------iloadR S + R s ini RA load outi = ---------- = -----------------------------i sR out + R loadR-------------------- SAR S + R iscin(1.30)In Sections 1.9 and 1.10 we presented the voltage and current amplifier equivalent circuits alsoknown as circuit models. Two more circuit models are the transresistance and transconductanceequivalent circuits and there are introduced in Exercises 1.4 and 1.5 respectively.1−20Electronic Devices and Amplifier Circuits with MATLAB Computing, Second EditionCopyright © Orchard Publications