Q. In the circuit shown, A and B are the inputs and F is the output. What is the functionality of the circuit?
(A) Latch
(B) XNOR
(C) SRAM Cell
(D) XOR
Ans: XNOR
Solution:
Case A:
A = 0, B = 0
NMOS 1 → OFF
NMOS 2 → OFF
PMOS 3 → ON
PMOS 4 → ON
Output = 1
Case B and Case C
A = 0, B = 1 or
A = 1, B = 0
In both cases either of NMOS is ON and one of the PMOS is OFF.
Case D:
A = 1, B = 1
Both NMOS are ON
NMOS will pass logic high from input A and B
F = 1
Truth Table,