Question

Question 4

a) Explain the operation of a CMOS transmission gate, illustrating the component symbol, MOS transistor circuit and function table. [3 marks]

b) Draw the XNOR (F = (A.B + A.B) logic circuit implemented using

CMOS transistor-based logic.

CMOS transmission gates.

Compare the transistor count for each implementation. [4 marks]

c) Draw and label a CMOS transmission gate circuit for a 4-to-1 multiplexer, using the following signal names:

sel(1:0) input data path select signal

muxIn(3:0) 4 x 1-bit input data signals

muxOut 1-bit output data signal

Illustrate the state of all circuit nodes for the following input signal states: sel = “10”, muxIn = “0101”. [5 marks]

Answer 1