(MOSFET) Consider the amplifier circuit below. The NMOS has: Vt = 1.5 V (1/2)kn'(W/L) = 50 mA/V2. Approximate λ = 0. Assume the two caps shown in the circuit are shorts at the frequency of interest a) What is the topology (CS, CD, CG?) b) Find the DC operating conditions. c) Sketch the small signal model. d) Find the input resistance. Rs is part of the signal generator, not the amplifier. e) Find the output resistance. f) Defining Vin as the node between the 30 -ohm resistor and C1, find the small-signal gain Vout /Vin. g) Find the small-signal gain Vout /Vs.
The circuit shown above is a MOS differential amplifier with the drain resistors RD implemented using diode-connected PMOS transistors, M3 and M4. Let M1 and M2 be matched, and M3 and M4 be matched. If λ>0 and gm ro >> 1: (a) Use circuit splitting technique to derive an expression for the differential voltage gain (Ad) (b) Determine the common-mode gain (A_CM) assuming that the tail current source (Iss) is non-ideal so that it has a finite output resistance Rss (parallel with the tail current source)
Consider a CMOS process for which Lmin = 0.18 μm, tox = 4 nm, μn = 450 cm2 /V•s, and Vt = 0.5 V. (a) Find Cox and kn’. (b) For an NMOS transistor with W/L = 2.4 μm/0.18 μm, calculate the values of VOV , VGS , and VDSmin needed to operate the transistor in the saturation region with a dc current ID = 0.5 mA. (c) For the device in (b), find the values of VOV and VGS required to cause the device to operate as a 500-Ω resistor for very small vDS.
A particular MOSFET for which Vtn = 0.4 V and kn'(W/L) = 2 mA/V2 is to be operated in the saturation region. If iD is to be 50 μA, find the required vGS and the minimum required vDS . Repeat for iD = 200 μA.
Consider the circuit in Fig. P11.52 as a transconductance amplifier with input Vs and output Io. The transistor is specified in terms of its gm and ro. (a) Sketch the small-signal equivalent circuit using the hybrid-π model of the MOSFET and convince yourself that the feedback circuit is comprised of resistor RF. (b) Find the A circuit and the β circuit. (c) Derive expressions for A, β, (1+Aβ), Af, Ro, and Rof.