Select Gate
AND Gate Simulator
Truth Table
📐 Logic Gate Reference
AND
Q = A · B
Output HIGH only when ALL inputs are HIGH
OR
Q = A + B
Output HIGH when ANY input is HIGH
NOT (Inverter)
Q = Ā
Output is always opposite of input
NAND
Q = ̄(A · B)
NOT AND — universal gate, can build any circuit
NOR
Q = ̄(A + B)
NOT OR — universal gate
XOR (Exclusive OR)
Q = A ⊕ B
HIGH when inputs are DIFFERENT
XNOR
Q = ̄(A ⊕ B)
HIGH when inputs are the SAME
❓ FAQ
What is a universal gate?
NAND and NOR are called universal gates because any logic function can be built using only NAND gates (or only NOR gates). For example, a NOT gate is just a NAND gate with both inputs tied together. This is why NAND and NOR are the most commonly implemented gates in digital ICs.
What is the difference between XOR and OR?
OR outputs HIGH when at least one input is HIGH (including when both are HIGH). XOR (Exclusive OR) outputs HIGH only when exactly one input is HIGH — it outputs LOW when both inputs are HIGH. XOR is commonly used in binary adders and parity checkers.
How are logic gates implemented in hardware?
Modern logic gates are built from CMOS transistors. An AND gate typically uses 4 transistors (NAND + NOT). CMOS gates consume power only during switching, making them ideal for battery-powered devices. Common IC families include 74HC (high-speed CMOS) and 74LS (low-power Schottky TTL).