D 13.38 For the folded-cascode circuit of Fig. 13.9, let the total capacitance to ground at each of the source nodes of Q3 and Q4 be denoted CP. Assuming that the incremental resistance between the drain of Q3 and ground is small, show that the pole that arises at the interface between the first and second stages has a frequency fP ≃ gm3/2πCP. Now, if this is the only nondominant pole, what is the largest value that CP can be (expressed as a fraction of CL) while a phase margin of 80° is achieved? Assume that all transistors are operated at the same bias current and overdrive voltage. 0.176CL