Consider the basic two-transistor NMOS current source in Figure 10.16. The circuit parameters are \(V^{+}=+5 \mathrm{~V}, V^{-}=-5 \mathrm{~V}\), and \(I_{\mathrm{REF}}=250 \mu \mathrm{A}\). The transistor parameters are \(V_{T N}=1 \mathrm{~V}, k_{n}^{\prime}=80 \mu \mathrm{A} / \mathrm{V}^{2}\), and \(\lambda=\) \(0.02 \mathrm{~V}^{-1}\).

(a) For \((W / L)_{1}=(W / L)_{2}=3\), find \(I_{O}\) for (i) \(V_{D S 2}=3 \mathrm{~V}\), (ii) \(V_{D S 2}=4.5 \mathrm{~V}\), and (iii) \(V_{D S 2}=6 \mathrm{~V}\).

(b) Repeat part (a) for \((W / L)_{1}=3\) and \((W / L)_{2}=4.5\).

IREF V+ Ro ID2=10 + VDSI M M2 VDS2 + VGS V- Figure 10.16 Basic two-transistor MOSFET current source