Repeat Problem 9.31(a) for the common-gate compensation scheme in Fig. 9.22 a.

Data from Prob. 9.31 (a):

The Miller-compensated two-stage op amp in Fig. 9.25 can be modeled as shown in Fig. 9.26. In the model, let g_m1 = 0.5 mA/V, R₁ = 200 kΩ, g_m6 = 2 mA/V, R₂ = 100 kΩ, C₁ = 0.1 pF, and C₂ = 8 pF.

(a) Assume the op amp is connected in negative feedback with f = 0.5. What is the value of C that gives a 45° phase margin? Assume the right half-plane (RHP) zero has been eliminated, and assume the feedback network does not load the op amp.

Fig. 9.25:

Figure 9.22 a:

Vpp , M5 Mg M2 M1 Vo Rz -W-- V; M6 IBIAS M4 -Vss VDD V. M11 in+ in- -Vss