16.31 Consider the CMOS inverter in Figure 16.21 biased at VDD = 2.5 V. The transistor parameters are VTN = 0.4 V, VTP = −0.4 V, and Kn = Kp = 100 μA/V2. (a) Find the transition points for the p-channel and n− channel transistors. (b) Sketch the voltage transfer characteristics, including the appropriate voltage values at the transition points. (c) Determine vO for vI = 1.1 V and vI = 1.4 V. Figure 16.21 CMOS inverter
A 0.13 μm CMOS fabrication process is specified to have μnCox = 511 μA/V2, μpCox = 128 μA/V2, Vtn = −Vtp = 0.4 V, VAn′ = 5 V/μm, and |VAp′| = 6 V/μm are the Early voltages (connected to channel length modulation, rO = VA/ID). Consider an n-channel device and a p-channel device fabricated in this process with equal channel lengths L = 0.26 μm and with equal widths W = 2.6 μm. (a) If both the NMOS and PMOS transistors specified above are operated at |VOV| = 0.2 V, find the current ID, the voltage VGS, the transconductance gm, and the output resistance ro of each device. Also specify the range of the voltage across the device for operation in the saturation mode to be obtained. (b) If while keeping |Vov| and L unchanged the PMOS device is to have an equal transconductance to that of the NMOS transistor, what device parameter must be changed and to what value? Also, find the new values of ID and ro of the modified PMOS transistor.
The transistors shown in the circuit below have the same VT and μnCox as 0.6 V and 200 μA/V2 respectively. The value of R1 (in kΩ) if the current through Q1 is 0.2 mA. Assume (W/L)1 = 10. Answer: kΩ
In the amplifier circuit shown in Fig. Q5, the BJT Q1 has β = 100 and VA = 100 V. The MOSFETs, M1 and M2, are identical with VTH = −1.0 V, Kp = 2 mA/V2 and they do not experience Channel Length Modulation effect. The temperature is 300 K. Fig. Q5 The BJT Q1 operates in the forward active mode and its collector current, IC, Q1 = 1.6 mA. Ignore the Early effect of the BJT when performing DC analysis. (a) Determine the drain current of the MOSFET M2, ID, M2. (6 marks) (b) Determine R3 that will give rise to the desired IC, Q1. (4 marks) (c) Determine the values of the 2-port network equivalent parameters of the amplifier: Gm (or Av), Rin and Rout. (8 marks) (d) Determine the gain (vout/vs) of the amplifier. (2 marks)