MOSFET's On-Resistance For one NMOS FET, if VGS > VTH and VDS ≪ VGS−VTH, it operates in the triode linear region and can be viewed as one linear resistor Ron = VDSID = 1 μnCoxWL(VGS−VTH) Since its on-resistance Ron depends on VGS, it is one voltage-controlled resistor and can be used in applications such as signal attenuation. In the lecture on Week 11's Thursday, we discussed the following circuit. If the MOSFET M1 is swapped with the resistor RL, we have another signal attenuation circuit as shown below In this new design, RL = 320 Ω, μnCox = 200 μA/V−2, VTH = 400 mV. If WL = 25 and VG = 0.8 V, what is the value of vout vin ? If VG = 2.4 V and vout vin = 0.8, what is the value of WL for M1?
Figure 2: For Questions, 4, 5, 6 and 7. For the difference amplifier circuit shown Figure 2, IQ = 400 μA, Ro = 125 kΩ, RC = 28.5 kΩ. For all the transistors: β = 100; VA = ∞; VBE(on) = 0.7 V. Assume the transistors are matched. 4. For the circuit shown in Figure 2, what is the value of gm for transistor Q1? (a) 3.421 mA/V (b) 2.675 mA/V (c) 9.564 mA/V(d) 7.616 mA/V (e) None of the above For the circuit shown in Figure 2, what is the value of differential gain Ad = vo1/vd for single-ended output vo1 and vd = v1−v2 is the differential input? (a) Ad = −14 V/V -(b) Ad = −62 V/V (c) Ad = −56 V/V (d) Ad = −42 V/V (e) None of the above