7404

The 7404 is a hex inverter integrated circuit, part of the 7400-series TTL logic devices. It contains six independent inverting gates, each with one input and one output. The device is designed for operation from a standard 5-volt supply and is commonly packaged in a 14-pin DIP (DIL) with corresponding surface-mount versions such as SOIC-14 and TSSOP-14.

In operation, a high input yields a low output and a low input yields a high output. The gates are independent and can be used in parallel to drive larger loads but are limited by the device’s output current and fan-out. Like other 74xx devices, the 7404 is designed for digital logic levels typical of TTL families; input thresholds are biased so that moderately high voltages are recognized as logic high, and outputs drive TTL-compatible levels.

Common applications include signal inversion, buffering, and level-shifting in hobbyist and industrial digital circuits. Because it provides six identical inverters in one package, it is convenient for creating invert chains, timing elements, and basic logic units without adding extra chips.

Variants and successors include 74LS04 (low-power Schottky TTL), 74HC04 and 74HCT04 (CMOS variants), and other logic-family equivalents such as 74ACT04 and 74LVC04, which differ mainly in speed, power consumption, and input/output characteristics while preserving the same logical function.

History: The 7404 was part of the original TTL 7400-series introduced in the 1960s and 1970s by major manufacturers, and remains a staple in electronics education and hobbyist projects.