Design a BJT diff-amp with an active load similar to the configuration in Figure P11.70 except that the input devices are to be pnp transistors and the active load will have npn transistors. Using the same parameters as in Problem 11.70, determine the small-signal differential-mode voltage gain.

Data From Problem 11.70:-

Consider the circuit in Figure P11.70, in which the input transistors to the diff-amp are Darlington pairs. Assume transistor parameters of \(\beta(\mathrm{npn})=120, \beta(\mathrm{pnp})=80, V_{A}(\mathrm{npn})=100 \mathrm{~V}\), and \(V_{A}(\mathrm{pnp})=80 \mathrm{~V}\). Let the power supply voltages be \(\pm 10 \mathrm{~V}\) and let \(I_{Q}=1 \mathrm{~mA}\).

(a) Determine the output resistance \(R_{o}\).

(b) Calculate the differential-mode voltage gain.

(c) Find the differential-mode input resistance \(R_{i d}\).

Transcribed Image Text:

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