Chapter 4, Problem 4.55P

(a)

To determine

To prove: The relation $\frac{\Delta V_0}{I_L}=-\left(r_d\parallel R\right)$ under given conditions for voltage regulator circuit.

(b)

To determine

To prove: The relation $\frac{\Delta V_0}{I_L}=-\frac{V_T}{I_D}\frac{V^{+}-0.7}{V^{+}-0.7+V_T}$ for the given conditions.

To select: The lowest possible value of $I_D$ that will result in load regulation.

To find: The value of R for the given value of $V^{+}$ .

Also, the diode required in terms of its current.

(c)

To determine

To modify: The expression derived in sub part (b) for m diodes connected in series.