Consider the multistage bipolar circuit in Figure P11.90, in which dc base currents are negligible. Assume the transistor parameters are \(\beta=120\), \(V_{B E}\) (on) \(=0.7 \mathrm{~V}\), and \(V_{A}=\infty\). The output resistance of the constant current source is \(R_{o}=200 \mathrm{k} \Omega\).

(a) For \(v_{1}=v_{2}=-1.5 \mathrm{~V}\), design the circuit such that \(v_{O 2}=v_{O}=0, I_{C Q 3}=0.25 \mathrm{~mA}\), and \(I_{C Q 4}=2 \mathrm{~mA}\).

(b) Assuming \(C_{E}\) acts as a short circuit, determine the differential-mode voltage gains \(A_{d 1}=v_{o 2} / v_{d}\) and \(A_{d}=v_{o} / v_{d}\).

(c) Determine the commonmode gains \(A_{c m 1}=v_{o 2} / v_{d}\) and \(A_{c m}=v_{o} / v_{d}\), and the overall \(\mathrm{CMRR}_{\mathrm{dB}}\).

Transcribed Image Text:

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