Draw a small$-$signal equivalent circuit for the inverting amplifier shown in Fig. $1,$ including the transistor capacitances $C_{gs},C_{gd}$ and $C_{bd}.$ Find an expression for the transfer function $A_v(j)=V_o\frac{j}{V_{in}}(j)$ and sketch the frequency response in a Bode plot, assuming the following values: $g_m=1\mathrm{.}0m\frac{A}{V},r_{ds}=75k,C_{gs}=120fF,C_{gd}=6fF$ and $C_{bd}=60fF.$ Find the lowfrequency gain, $f_{-3dB}$ and $f_{\text{U}\text{G}\text{B}}.$

$10$

FIg. $1$