Chapter 11, Problem 11.51P

Consider the MOSFET diff-amp with the configuration in Figure P11.33. The circuit parameters are $V^{+}=3\text{V},V^{-}=-3\text{V},$ and $I_Q=0.2\text{mA}$ $k_n^{\prime }=100\mu \text{A}/{\text{V}}^2,W/L=10,$ and $\lambda =0.$ The range of the common mode input voltage is to be $-1.5\le v_{cm}\le +1.5\text{V},$ and the common mode rejection ratio is to be ${\text{CMRR}}_{\text{dB}}=50\text{dB}$ . (a) Design the diff-amp to produce the maximum possible differential-mode voltage gain. (b) Design an all MOSFET current source to produce the desired bias current and CMRR. The minimum $W/L$ ratio of any transistor is to be 0.8 and assume $\lambda =0.02{\text{V}}^{-1}$ for all transistors in the current source circuit.