NAND Gate
The two-input NAND gate implements the complement of AND. NAND is functionally complete, so any Boolean function can be expressed using NAND gates alone.
Overview
The two-input NAND gate implements the complement of AND. NAND is functionally complete: Boolean functions can be expressed using NAND gates alone.
DigiSim Interface
| Direction | Pins | Behavior |
|---|---|---|
| Input | A, B | Two one-bit operands. |
| Output | Y | Driven complement of A AND B. |
Truth Table
A defined LOW forces HIGH even beside X; otherwise a relevant driven unknown produces X.
Released Z inputs follow Logic Lab's LOW sampling convention.
Simulation Boundary
Functional completeness is a statement about Boolean expressiveness. It does not define a physical gate implementation, timing, power, drive capability, or IC package.
Learning Path
Frequently Asked Questions
What is a NAND gate?
A NAND gate is an AND gate followed by a NOT gate. It outputs 0 only when all inputs are 1; otherwise, it outputs 1.
Why is NAND called a universal gate?
NAND is universal because any Boolean function can be constructed from NAND gates alone. This is useful for reasoning and some implementations, although practical cell libraries normally combine several gate types.
How do I build an AND gate from NAND gates?
Feed A and B into the first NAND, then connect its output to both inputs of a second NAND. The second gate acts as an inverter, so the pair produces A AND B.