OR gate

The OR gate is a digital logic gate that implements logical disjunction - it behaves according to the truth table  to the right. A HIGH output (1) results if one or both the inputs to the gate are HIGH (1). If neither input is HIGH, a LOW output (0) results. In another sense, the function of OR effectively finds the maximum between two binary digits, just as the complementary AND function finds the minimum.

OR Gates are basic logic gates, and as such they are available in TTL and CMOS ICs logic families. The standard 4000 series CMOS  IC is the 4071, which includes four independent two-input OR gates. The traditional TTL version is the 7432. There are many offshoots of the original 7432 OR gate. All have the same pinout but different internal architecture, allowing them to operate in different voltage ranges and/or at higher speeds. In addition to the standard 2-Input OR Gate, 3- and 4-Input OR Gates are also available. In the CMOS series, these are:

* 4075: Triple 3-Input OR Gate

* 4072: Dual 4-Input OR Gate

TTL variations include:

* 74LS32: Quad 2-input OR gate (Low power Schottky version)

* 74HC32: Quad 2-input OR gate (High Speed CMOS version) - has lower current comsumption/wider Voltage range

* 74LVC32: Low voltage CMOS version of the same.