Figure 541
the MOSFET in the Circuit of Fig $V_{t}=$ $1 \mathrm{~V}$

Figure 5.4.1
The MOSFET in the circuit of Fig. 5.4.1 has $V_{t}=$ $1 \mathrm{~V}$ and $k_{n}=2 \mathrm{~mA} / \mathrm{V}^{2}$ , and the Early effect can be neglected.
(a) Find the values of $R_{S}$ and $R_{D}$ that result in the MOSFET operating with an overdrive voltage of $0.5 \mathrm{~V}$ and a drain voltage of $1.5 \mathrm{~V}$ . What is the resulting $I_{D}$ value?
(b) If $R_{L}$ is reduced from $15 \mathrm{k} \Omega$ to $10 \mathrm{k} \Omega$ , what does $V_{D}$ become?
(c) If $R_{L}$ is disconnected, what does $V_{D}$ become?
(d) With $R_{L}$ disconnected, what is the largest $R_{D}$ that can be used while the MOSFET is remaining in saturation?