Chapter 11, Problem 11.75P

Consider the fully cascoded diff-amp in Figure 11.37 . Assume $I_Q=80\mu \text{A}$ and transistor parameters of: $V_{TN}=0.8\text{V},k_n^{\prime }=60\mu \text{A}/{\text{V}}^2$ ${\lambda }_n=0.015{\text{V}}^{-1},V_{TP}=-0.8\text{V},k_p^{\prime }=25\mu \text{A}/{\text{V}}^2,$ and ${\lambda }_p=0.02{\text{V}}^{-1}$ The transistor width-to-length ratios are $W/L=60/4$ for transistors $M_1-M_4,W/L=40/4$ for transistors $M_5-M_6,$ and $W/L=4/4$ for transistors $M_7-M_8.$ (a) Determine the output resistance of the diff-amp. (b) Calculate the differential-mode voltage gain of the diff-amp. (c) Find the common-mode voltage gain of the diff-amp using a computer simulation.