SIM D *11.40 Figure P11.40 shows a series-shunt ampli- fier with a feedback factor 8 =...

 

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SIM D *11.40 Figure P11.40 shows a series-shunt ampli- fier with a feedback factor 8 = 1. The amplifier is designed so that v = 0 for vs = 0, with small deviations in v, from 0 V dc being minimized by the negative-feedback action. The technology utilized has k=2= 120 µA/V², |V₂|=0.7 V, and V=24 V/μm. (a) Show that the feedback is negative. (b) With the feedback loop opened at the gate of Q₂, and the gate terminals of Q₁ and Q₂ grounded, find the de current and the overdrive voltage at which each of Q, to Qs is operating. Ignore the Early effect. Also find the de voltage at the output. (c) Find g and r, of each of the five transistors. (d) Find expressions and values of A and R. Assume that the bias current sources are ideal. (e) Find the gain with feedback, A,, and the output resistance Rout (f) How would you modify the circuit to realize a closed-loop voltage gain of 5 V/V? What is the value of output resistance obtained? Us Figure P11.40 Q3 (40/1) +2.5 V 2₂ (20/1) (20/1) 200 μA 24 (120/1) 1 ls 300 μα -2.5 V 0.8 mA (20/1) -0%b Rout SIM D *11.40 Figure P11.40 shows a series-shunt ampli- fier with a feedback factor 8 = 1. The amplifier is designed so that v = 0 for vs = 0, with small deviations in v, from 0 V dc being minimized by the negative-feedback action. The technology utilized has k=2= 120 µA/V², |V₂|=0.7 V, and V=24 V/μm. (a) Show that the feedback is negative. (b) With the feedback loop opened at the gate of Q₂, and the gate terminals of Q₁ and Q₂ grounded, find the de current and the overdrive voltage at which each of Q, to Qs is operating. Ignore the Early effect. Also find the de voltage at the output. (c) Find g and r, of each of the five transistors. (d) Find expressions and values of A and R. Assume that the bias current sources are ideal. (e) Find the gain with feedback, A,, and the output resistance Rout (f) How would you modify the circuit to realize a closed-loop voltage gain of 5 V/V? What is the value of output resistance obtained? Us Figure P11.40 Q3 (40/1) +2.5 V 2₂ (20/1) (20/1) 200 μA 24 (120/1) 1 ls 300 μα -2.5 V 0.8 mA (20/1) -0%b Rout

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