Consider a CMOS inverter with the following parameters: nMOS VT0,n = 0.6 V unCox = 60 uA/V2 (W/L)n = 8 pMOS VT0,P = -0.7 V upCox = 25 uA/V2 (W/L)p = 12 Calculate the noise margins and the switching threshold (Vth) of this circuit. The power supply voltage is VDD = 3.3 V.
Design of a CMOS inverter circuit: Use the same device parameters as in Problem 5.6. The power supply voltage is VDD = 3.3 V. The channel length of both transistors is Ln = Lp = 0.8 um. (a) Determine the (Wn/Wp) ratio so that the switching (inversion) threshold voltage of the circuit is Vth = 1.4 V. (b) The CMOS fabrication process used to manufacture this inverter allows a variation of the VT0,n value by
Consider a CMOS inverter, with the following device parameters: nMOS VT0,n = 0.6 V unCox = 60 uA/V2 pMOS VT0,p = -0.8 V upCox = 20 uA/V2 Also: VDD = 3 V (a) Determine the (W/L) ratios of the nMOS and the PMOS transistor such that the switching threshold is Vth = 1.5 V. (b) Plot the VTC of the CMOS inverter using SPICE. (c) Determine the VTC of the inverter for lambda = 0.05 V-1 and 0.1 V-1. (d) Discuss how the noise margins are influenced by non-zero lambda, value. Note that transistors with very short channel lengths (manufactured with sub-micron design rules) tend to have larger
Consider the CMOS inverter designed in Problem 5.9 above, with λ = 0.1 V-1. Now consider a cascade connection of four identical inverters, as shown below. (a) If the input voltage is Vin = 1.55 V, find Vout1, vout2, vout3 and vout4 (Note that this requires solving KCL equations for each subsequent stage, using the nonzero a value). (b) How many stages are necessary to restore a true logic output level? (c) Verify your result with SPICE simulation.