1. Warm up

  1. Use a combination of CMOS gates (represented by their symbols) to generate the following functions from inputs A, B, and C.

    1. \(Y = A\) (buffer)




    2. \(Y = A\bar{B} + \bar{A}B\) (XOR)




    3. \(Y = \bar{A} \bar{B} + AB\) (XNOR)




    4. \(Y = AB + BC + AC\) (majority)




  2. Sketch a transistor-level schematic for a CMOS 4-input NOR gate.





2. Pass transistors and transmission gates

Book § 1.4.6, page 12.

n pass



p pass



fig1 20

fig1 21

  • TXgates require 2 control inputs. \(A\text{ and }\bar{A}\), or true and complementary

  • Just as common as other types of gates.

  • Super nice for multiplexers: