In order to make up for the generally poorer characteristics of planar pnp BJTs, the output stage of Fig. P4.102 utilizes the quasi-complementary Darlington confi guration discussed in the text in...

In order to make up for the generally poorer characteristics of planar pnp BJTs, the output stage of Fig. P4.102 utilizes the quasi-complementary Darlington confi guration discussed in the text in connection. (a) Assuming Fp 5 120, Is1 5 Is3 5 Is4 5 Is5 5 10 fA, and Is2 5 1 fA, estimate all currents and voltages in the circuit if R 5 20 kV, I1 5 I2 5 200 A, and vI has been adjusted so that vO 5 0. (b) What is the required value of vI ? (c) Find R so that vO 5 0 for vI 5 0.