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For the two-stage n-MOSFET amplifier circuit shown below, assume that K′ = 1mA/V2 and VT = 1V for all MOSFETs. (a) Find the DC voltages VIN, VOUT1 and VOUT2 . (b) Draw the small-signal model for the circuit assuming a small signal source is applied at the node marked vIN. Find the small signal voltage gains: A1 = vout1/vin; A2 = vout2/vout1; ATotal = vout2/vin . (c) What is the small-signal input resistance, rin?

For the two-stage n-MOSFET amplifier circuit shown below, assume that K′ = 1mA/V2 and VT = 1V for all MOSFETs. (a) Find the DC voltages VIN, VOUT1 and VOUT2 . (b) Draw the small-signal model for the circuit assuming a small signal source is applied at the node marked vIN. Find the small signal voltage gains: A1 = vout1/vin; A2 = vout2/vout1; ATotal = vout2/vin . (c) What is the small-signal input resistance, rin?

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  1. For the two-stage n-MOSFET amplifier circuit shown below, assume that K ′ = 1 m A / V 2 and V T = 1 V for all MOSFETs. (a) Find the DC voltages V I N , V OUT1 and V oUT2 . (b) Draw the small-signal model for the circuit assuming a small signal source is applied at the node marked v I N . Find the small signal voltage gains: A 1 = v out 1 / v in ; A 2 = v out 2 / v out 1 ; A Total = v out / v in . (c) What is the small-signal input resistance, r i n ?

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Q6. An amplifier circuit using an n-MOSFET is shown in Fig. Q6. The n-MOSFET has the following parameters: Kn = 1 mA/V2 and λ = 0.02 V−1. vin is a small signal AC voltage source. Fig. Q6 (a) Calculate the DC gate voltage, VG. (b) Assuming that the n-MOSFET is operating in the saturation region and neglecting channel length modulation, calculate the threshold voltage, VTHN, given that the voltage drop across the dc current source, IBUS, has been designed to be approximately 0 V. Verify that the n-MOSFET is operating in the saturation region. (c) Find the values of small signal parameters gm and ro of the n-MOSFET. (d) What is the configuration of the amplifier circuit? (e) Draw the small signal ac equivalent circuit of Fig. Q6. You may assume that in the small signal ac equivalent circuit, all the coupling capacitors behave like short circuits. (f) Calculate the input resistance, Rin, and output resistance, Rout . (g) Calculate the voltage gain, vout/vin.

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In the circuit below, the MOSFET has K = 2 mA/V2 and VT = 1 V. The BJT has β = 100. (a) Find the minimum value of VIN for which Q1 will operate in forward active and M1 will operate in saturation. (b) Set VIN = 3 V. Find VOUT and IDS. Draw the small-signal model. (c) Find the small-signal voltage gain A = vout/vin. (d) Find the small-signal input resistance, rin. (e) Find the small-signal output resistance, rout .
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