Chapter 6, Problem 6.2TYU

Consider the circuit in Figure 6.18. The circuit parameters are $V^{+}=3.3\text{V}$ , $V_{BB}=2.455\text{V}$ , $R_B=80\text{kΩ}$ , and $R_C=7\text{kΩ}$ . The transistor parameters are $\beta =110$ , $V_{BE}\text{(on)}=0.7\text{V}$ , and $V_A=80\text{V}$ . (a) Determine $I_{CQ}$ and $V_{ECQ}$ . (b) Find $g_m,r_{\pi }$ , and $r_o$ . (c) Determine the small−signal voltage gain $A_{\upsilon }={\upsilon }_o/{\upsilon }_s$ . (d) Find the small−signal input and output resistances $R_i$ and $R_o$ , respectively. (Ans. (a) $I_{CQ}\text{=0}\text{.2mA}$ , $V_{ECQ}=1.9\text{V}$ ; (b) $g_m=7.692\text{mA/V}$ , $r_{\pi }=14.3\text{kΩ}$ , $r_o=400\text{kΩ}$ ; (c) $A_{\upsilon }=-8.02$ ; (d) $R_i=94.3\text{kΩ}$ , $R_o=6.88\text{kΩ}$ )