Chapter 8, Problem 8.8TYU

Consider the class−AB output stage shown in Figure 8.37. The transistor parameters are ${\beta }_n=100$ and $I_{Sn}=5\times {10}^{-16}$ A for the npn device, and ${\beta }_P=100$ and $I_{Sp}=8\times {10}^{-16}$ A for the pnp device. (a) What value of $V_{BB}$ will establish quiescent collector currents of $I_{CQ}=1\text{mA}$ with ${\upsilon }_o=0$ . (b) What are the values of ${\upsilon }_{BEn}$ and ${\upsilon }_{BEp}$ ? (c) What must be the value of ${\upsilon }_I$ such that ${\upsilon }_o=0$ . (Ans. (a) $V_{BB}=\text{1}\text{.4606V}$ ; (b) ${\upsilon }_{BEn}=0.7\text{364V}$ , ${\upsilon }_{BEp}=0.7242\text{V}$ ; (c) ${\upsilon }_I=6.\text{1mV}$ )

Figure 8.37 Figure for Exercise TYU 8.8