Chapter 6, Problem 6.12EP

For the circuit shown in Figure 6.49, let $V_{CC}=12\text{V}$ , $R_E=30\text{Ω}$ , $R_1=1.3\text{kΩ}$ , $R_2=4.2\text{kΩ}$ , and $R_S=0$ . The transistor parameters are $\beta =80$ , $V_{BE}\text{(on)}=0.7\text{V}$ , and $V_A=75\text{V}$ . (a) Determine the quiescent values $I_{EQ}$ and $V_{CEQ}$ . (b) Find the small−signal voltage gain $A_{\upsilon }=V_o/V_s$ . (c) Determine the input resistance looking into the base of the transistor. (Ans. (a) $I_{EQ}=0.2\text{A}$ , $V_{CEQ}=6\text{V}$ ; (b) $A_{\upsilon }=0.9954$ ; (c) $R_{ib}=2.27\text{kΩ}$ )