Question

Notify Me Bookmark

The CMOS transmission gate shown has an input voltage of 2.0 V when it turns off. The W/L of the n-channel is 4 μm/0.6 μm and the W/L of the p-channel is 8 μm/0.6 μm. Estimate the change in output voltage due to clock feedthrough. You may assume the total parasitic capacitance between the output node and ground is 100 fF, that VDD = 3.3 V, and that the clock signal changes very fast. Ignore the changes due to overlap capacitance. Assume, VTN0 = 0.7 V, VTP0 = −0.8 V, Cox = 3.4 fF/m2.

The CMOS transmission gate shown has an input voltage of 2.0 V when it turns off. The W/L of the n-channel is 4 μm/0.6 μm and the W/L of the p-channel is 8 μm/0.6 μm. Estimate the change in output voltage due to clock feedthrough. You may assume the total parasitic capacitance between the output node and ground is 100 fF, that VDD = 3.3 V, and that the clock signal changes very fast. Ignore the changes due to overlap capacitance. Assume, VTN0 = 0.7 V, VTP0 = −0.8 V, Cox = 3.4 fF/m2.

Image text
The CMOS transmission gate shown has an input voltage of 2.0 V when it turns off. The W/L of the n -channel is 4 μ m / 0.6 μ m and the W / L of the p -channel is 8 μ m / 0.6 μ m . Estimate the change in output voltage due to clock feedthrough. You may assume the total parasitic capacitance between the output node and ground is 100 f F , that V D D = 3.3 V , and that the clock signal changes very fast. Ignore the changes due to overlap capacitance. Assume, V T N 0 = 0.7 V , V T P 0 = − 0.8 V , C o x = 3.4 f F / m 2 .

Detailed Answer

0 0

Please enter your email here. You will get email when this question is answered by our tutor.

Doubtrix Logo

Problem is not yet solved!

Click on Notify me to get email when question is answered.

Join Doubtrix with 7-days free trial

  • Icon Correct & Verified Answers
  • Icon No AI-Generated Answers
  • Icon Video Solution for Difficult Questions
  • Icon Work With Experts to Reach at Correct Answers
Notify me Login Sign Up

Similar/Related Questions

The CMOS transmission gate shown has an input voltage of 1.0 V when it turns off. The W/L of the n-channel is 4 μm/0.6 μm and the W/L of the p-channel is 8 μm/0.6 μm. Estimate the change in output voltage due to clock feedthrough. You may assume the total parasitic capacitance between the output node and ground is 50 fF, that VDD = 3.3 V, and that the clock signal changes very fast. Ignore the changes due to overlap capacitance. Assume, VTN0 = 1.1 V, VTP0 = −1.2 V, Cox = 3.4 fF/μm2.

Solution
0 0

For the circuit shown in Figure 2, VDD = 5 V, and transistors M1 and M2 have properties µnCox = 200µA/V2, (W/L) = 10, Vt0 = 0.7 V, and λ = 0. You may neglect the body effect below, unless you are specifically asked to consider it. Figure 2. Circuit for Problem 2. a) Draw the circuit above, and label the drain, gate, source, and bulk nodes for both transistors, using labels VD1, VG1, VS1, and VB1 for the drain, gate, source, and bulk nodes of device M1, respectively, and similarly for M2. In total, there should be 8 labels in your schematic. For this part, assume the transistors are in saturation. b) Determine the valid input range for the circuit under consideration; that is, determine the range on the input voltage Vin such that transistors M1 and M2 are operating in the saturation region. Note that, in your analysis, you are not constrained to Vin values between 0 V and VDD, inclusive; e.g., if Vin = 100 V keeps both of the transistors in saturation, then Vin = 100 V should be included in your range of valid input voltages. Your answer to this part should take the form Vin,low ≤ Vin ≤ Vin,high ; hopefully, it is obvious that you are being asked to provide numerical answers for the lower- and upper-bounds Vin,low and Vin,high , respectively. c) For the valid input range that you determined in part (b), determine the corresponding output voltage range; that is, determine Vout,low ≤ Vout ≤ Vout,high when the input is constrained to Vin,low ≤ Vin ≤ Vin,high. . As before, you should report numerical values for the lower- and upper-bounds Vout,low and Vout,high, , respectively. d) Determine the "on voltage" VON2 (or, as in the Sedra/Smith textbook, the "overdrive voltage") and drain current ID2 of transistor M2 over the range of valid input voltages. Also, determine the drain current ID1 of M1 over the valid input range. e) If you were to consider it, would any of the transistors in the circuit above be affected by the body effect? If "yes," then list the device (or, devices, as the case may be). Qualitatively speaking, how would your answers to parts (b) and (c) change if you were to take the body effect into account? Explain your reasoning.
Solution
0 0

Q1. Consider the CMOS inverter of which the transistors have the following parameters: μnCox = 4μpCox = 160 μA/V2, ∣γ| = 0.5 V1/2, 2Φf = 0.5 V, λ = 0.001 V−1, Vtno = 0.6 V, Vtpo = −0.8 V, (W/L)n = 1 and (W/L)p = 4. The supply voltage VDD = 3.3 V. The capacitive load at the output node is 20 pF. The input voltage Vin is expected to be a perfect periodic square wave with full swing (low level : 0 V, high level: VDD). (a) Calculate tl, the time required for the output voltage Vout to change from 0 V to the threshold voltage of the inverter, using the average-current method. (b) Write the expression of calculation of t2, the time required for the output voltage Vout to change from 2.9 V to the 0.4 V, using the analytical method (integral). Then calculate t2 using the average-current method. (c) Determine the maximum frequency of the periodic square wave input so that the output signal will have a full swing in each cycle. (d) Calculate the peak value of in, the NMOS transistor current, during the transition, and its average value over a clock cycle T. (The average value here is not the same as the average-current in the "average-current method" for delay estimation) (e) If the capacitive load is now changed to be 250 pF, what can be done to make tl and t2 unchanged?
Solution
0 0