Design a voltage reference source as shown in Figure 9.42 to have an output voltage of \(12.0 \mathrm{~V}\). A Zener diode with a breakdown voltage of \(5.6 \mathrm{~V}\) is available. Assume the voltage regulation will be within specifications if the Zener diode current is within the range of \(1.2 \leq I_{Z} \leq 1.35\mathrm{~mA}\). The startup voltage \(V_{S}\) is to be \(10 \mathrm{~V}\).

R3 Vso ww R R ww ww RA D 12 + RF www IF -Vo Figure 9.42 Op-amp voltage reference circuit