(a) Obtain an expression for V_{0} in terms of V_{s}, R, and the reverse saturation current I_{s} of the transiostor.

(b) If R = 1$$\Omega $$, I_{s} = 1pA and the thermal voltage V_{T} = 25mV, then what is the value of the output voltage V_{0} for an input voltage V_{s} = 1V?

(c) Suppose that the transistor in the feedback path is replaced by a p-n junction diode with a reverse saturation current of I_{s}. The p-side of the diode is connected to node A and the n-side to node B. Then what is the expression for V_{0} in terms V_{s}, R and I_{s} ?

The characteristics of the diode are given by the relation I = I_{s} $$\left[ {{e^{{{qV} \over {KT}}}} - 1} \right],$$

Where V is the forward voltage across the diode

(a)Express V_{0} as a function of V_{i} assuming V_{i}> 0.

(b)If R = 100K$$\Omega $$ , I_{s} = 1$$\mu $$A and $${{KT} \over q}\,\, = \,\,25mV$$