Consider the BJT circuit called the "common-collector amplifier" shown in Figure 7.89. This BJT amplifier configuration is also called the source follower circuit. For this problem, use the piecewise-linear BJT model from Exercise 7.8. Assume that the BJT operates in its active region. a) Draw the active-region equivalent circuit of the BJT source follower by replacing the BJT by its piecewise-linear model. b) Assuming active region operation, determine vo in terms of v, R, RE, and the BJT parameter B. c) What is the value of vo when BRE >> R? d) Compute the value of vo given that v = 3 V, R = 10 ks, R = 100 k, = 100, and Vs = 10 V. e) Determine the range of values of up for which the BJT operates in its active region for the parameter values given in (d). What is the corresponding range of vo? VI + 1 wwwww R FIGURE 7.89 AVS ic iB c B E www RE Vo B iB + 0.4 V VBE (b) C ic oBig 0.6V iE E + VCE