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The MOSFET in the amplifier circuit in Figure 1 below has kn′W/L = 800 μA/V2 and Vt = 0,5 V. Analyse the dc bias circuit to determine ID, VS and VGS assuming λ = 0. Identify this amplifier configuration, draw an appropriate small-signal equivalent circuit diagram of this amplifier and hence calculate the overall signal voltage gain Avs = vo/vsig assuming λ = 0 Figure 1

The MOSFET in the amplifier circuit in Figure 1 below has kn′W/L = 800 μA/V2 and Vt = 0,5 V. Analyse the dc bias circuit to determine ID, VS and VGS assuming λ = 0. Identify this amplifier configuration, draw an appropriate small-signal equivalent circuit diagram of this amplifier and hence calculate the overall signal voltage gain Avs = vo/vsig assuming λ = 0 Figure 1

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The MOSFET in the amplifier circuit in Figure 1 below has k n ′ W / L = 800 μ A / V 2 and V t = 0 , 5 V . Analyse the dc bias circuit to determine I D , V S and V G S assuming λ = 0 . Identify this amplifier configuration, draw an appropriate small-signal equivalent circuit diagram of this amplifier and hence calculate the overall signal voltage gain A v s ≡ v o / v sig assuming λ = 0 Figure 1

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The MOSFET in the circuit below has Vt = 0.5 V and λ = 0. The dc voltages at the source and the drain are measured and found to be −0.75 V and +1.6 V, respectively. Assume all three capacitors to be very large. (a) Show that the MOSFET is operating in saturation and find VOV, RD, and gm. (b) Using Inspection Formulas, determine Rin, Rout, and calculate the overall voltage gain obtained when the switch S is connected to position 1. (c) Draw the small-signal equivalent circuit using the Hybrid-𝜋 model. (d) If, when the switch S is moved to position 2, the amplitude of vo drops to half its value, what do you estimate the value of Rs to be?
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Figure 1 shows a single stage common source MOSFET amplifier circuit. We wish to design the circuit to meet the following design specifications: Load Resistance: RL = 100 KΩ Input Resistance: Ri > 200 KΩ Mid-band Gain: Gv = Vo/Vi = −50 ± 20% Supply Voltage: +15 Volts Circuit Capacitors: CG = 10μF; CS = 47μF; CD = 10μF Figure 1. Common Source MOSFET Amplifier Pre-lab: (a) Design the amplifier to meet the specifications above by choosing values for resistors R1, R2, RD and RS. Begin your design by choosing an appropriate value for the bias current ID. If ID ≈ 0.3 mA, assume VT ≈ 1.7 V, Kn ≈ 0.02 A/V2 and VA = 100 V(λ = 0.01 V−1). Find the small signal approximation of the input resistance Rin where Rin = R1∥R2 Find the small signal approximation of the output resistance Ro, where Ro is given as Ro = RD∥RL∥ro. The small signal mid-band gain of the amplifier is given by Gv = −gmRo where gm = 2knID = kn(VGS−VT) Once you choose ID the DC biasing of the transistor can be found using simple rules of thumb. The voltage VG should be approximately equal to VDD/3 > VT. For maximum symmetry, VD should be biased at the midpoint between VD(Max) and VD(Min). Clearly, the maximum VD is VDD and the minimum VD > VG−Vt. For example, if Vt = 1.7 V and VG = 1/3VDD = 5 V, then VD ≈ 9 V for maximum symmetry.

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