Consider a CMOS inverter fabricated in a 0.25-um CMOS process for which VDD = 2.5 V, Vtn = -Vtp = 0.5 V, and unCox = 3.5 upCox = 115 uA/V2 . In addition, QN and QP have L = 0.25 um and (W/L)n = 1.5. Investigate the variation of VM with the ratio Wp/Wn. Specifically, calculate VM for (a) Wp = 3.5Wn (the matched case), (b) Wp = Wn (the minimum-size case); and (c) Wp = 2Wn (a compromise case). For cases (b) and (c), estimate the approximate reduction in NML and silicon area relative to the matched case (a).
For a technology in which Vtn = 0.3VDD, show that the maximum current that the inverter can sink while its low-output level does not exceed 0.1 VDD is 0.065 k
For a technology in which show Vtn = 0.2VDD that the maximum current that the inverter can sink while its low-output level does not exceed 0.1VDD is 0.075 kn'(W/L)nVDD. For VDD = 2.5V, kn' = 115 μA/V2, find (W/L) that permits this maximum current to be 0.5 mA.
For a technology in which Vin = 0.3 VDD, show that the maximum current that the inverter can sink while its low-output level doesn't exceed 0.1 VDD is 0.07kn'(W/L)nVDD^2
A CMOS inverter for which kn = 5kp = 200 uA/V2 and Vt = 0.5 V is connected as shown in Fig. P14.34 to a sinusoidal signal source having a Thevenin equivalent voltage of 0.1-V peak amplitude and resistance of 100 k?. What signal voltage appears at node A with vI = +1.5 V? With vI = -1.5 V?
There are situations in which QN and QP of the CMOS inverter are deliberately mismatched to realize a certain desired value for VM. Show that the value required of the parameter r of Eq. (14.40) is given by r = VM - Vtn/VDD - |Vtp| - VM For a 0.13-um process characterized by Vtn = -Vtp = 0.4V, VDD = 1.3V, and ?n = 4?p, find the ratio Wp/Wn required to obtain VM = 0.6VDD.
There are situations in which QN and QP of the CMOS inverter are deliberately mismatched to realize a certain desired value for VM. Show that the value required of the parameter r of Eq. (13.59) is given by r = VM - Vtn/VDD - |Vtp| - VM For a 0.18-um process characterized by Vtn = -Vtp = 0.5V, VDD = 1.8V, and ?n = 4?p, find the ratio Wp/Wn required to obtain VM = 0.6VDD.