13.59 Consider the 741 input stage as modeled in Fig. 13.24, with two additional npn diode-connected transistors, Q1a and Q2a, connected between the present npn and pnp devices, one per side. Assume βN = 200, βP = 50, and VAP = 50 V. Convince yourself that each of the additional devices will be biased at the same current as Q1 to Q4—let us assume 9.5 µA. What does Rid become? What does Gm1 become? What is the value of Ro4 now? What is the output resistance of the first stage, Ro1? (Assume the active load output resistance remains unchanged from Exercise 13.21 at 10.5 MΩ.) What is the new open-circuit voltage gain, Gm1Ro1? Compare these values with the original ones from Exercises 13.20–22, namely, Rid = 2.1 MΩ, Gm1 = 0.19 mA/V, Ro4 = 10.5 MΩ, Ro1 = 5.3 MΩ, and |Avo| = 1007 V/V.