The diff-amp in Figure 11.3 of the text has parameters \(V^{+}=+5 \mathrm{~V}\), \(V^{-}=-5 \mathrm{~V}, R_{C}=8 \mathrm{k} \Omega\), and \(I_{Q}=0.5 \mathrm{~mA}\). The transistor parameters are \(\beta=120, V_{B E}\) (on) \(=0.7 \mathrm{~V}\), and \(V_{A}=\infty\).

(a) Using Figure 11.3(a), determine the maximum common-mode input voltage \(v_{c m}\) that can be applied such that the transistors \(Q_{1}\) and \(Q_{2}\) remain biased in the active region.

(b) Using Figure 11.3(b), determine the change in \(v_{C 2}\) from its dc value if \(v_{d}=18 \mathrm{mV}\).

(c) Repeat part (b) if \(v_{d}=10 \mathrm{mV}\).

Figure 11.3:-

Transcribed Image Text:

Rc Rc VC2= lg RC V+-2 VCI= V+RC VE + Vem 02 22 (a) V+ www VC2= [V+ - (-AI) RC] VCI = 10+ AIRC [v+(+1) RC] Rc 52 + UBEL 12+1 221 (b) VBE2 Figure 11.3 Basic diff-amp with applied common-mode voltage and (b) basic diff-amp with applied differential-mode voltage