Semiconductor Electronics · Question 32

Which of the following circuits has the same output as that of the given circuit? [figure]

1. [figure]
2. [figure]
3. [figure]
4. [figure]

Answer

(1) [figure]

Solution

Upper AND gate: inputs A and B A B

Lower AND gate: inputs A and B AB

NOR gate: Y = A B + AB

= A( B + B) = A 1 = A

Circuit (A): a NAND gate with the single input A gives Y = A A = A

(B) gives AB, (C) gives B, (D) gives AB.

Answer: (1)