LearnTronics
AND, OR, and XOR Gate Symbols
Three familiar two-input gate shapes
Now we can introduce the gates that combine two statements or two digital signals.
AND — Y = A • B
The traditional AND symbol has a flat input side and a rounded output side. The output is 1 only when both inputs are 1.
OR — Y = A + B
The OR symbol has a curved input side and a pointed output. The output is 1 when A, B, or both are 1.
XOR — Y = A ⊕ B
XOR looks much like OR, but it has an extra curved line at the input side. Its output is 1 when the two inputs are different.
All three truth tables together
| A | B | A • B | A + B | A ⊕ B |
|---|---|---|---|---|
| 0 | 0 | 0 | 0 | 0 |
| 0 | 1 | 0 | 1 | 1 |
| 1 | 0 | 0 | 1 | 1 |
| 1 | 1 | 1 | 1 | 0 |
Symbol standards vary
The curved shapes shown here are the traditional American/ANSI-style symbols commonly seen in electronics. IEC drawings may use rectangular logic symbols instead. The Boolean function is what matters.
On these lessons the gate body carries the Boolean symbol — •, +, or ⊕ — rather than spelling the gate name inside it.