Chapter 1, Problem 1.9EP

(a) Consider the circuit shown in Figure 1.28. Let $V_{PS}=8\text{V}$ and $V_{\gamma }=0.7\text{V}$ , Assume $r_f=0$ . Calculate the value of R such that $I_D=1.20\text{mA}$ . (b) If $V_{PS}$ is reduced to 4 V and R is changed to $3.5\text{k}\Omega$ , determine the power dissipated in the diode. (Ans. (a) $6.08\text{k}\Omega$ , (b) 0.66 mW).