SN7405N

Hex Inverter with High-Voltage Open-Collector Outputs manufactured by Texas Instruments. This classic 14-pin digital logic integrated circuit packages six entirely independent logical inverter (NOT) gates built with 15V-rated open-collector output transistors. It functions by omitting an active internal pull-up transistor on its output stages, enabling the chip to pull lines exclusively down to ground while relying on an external pull-up resistor to safely shift signal voltages up to a custom external voltage rail (up to 15V) to drive peripheral loads or interface separate logic families. It was ubiquitously implemented to execute bidirectional multi-voltage logic translation, manage wired-AND system bus architectures, and drive high-current LED indicator arrays, status lamps, or solid-state relay coils across vintage 8-bit computing platforms and early arcade cabinets. (Industry Equals: Texas Instruments SN7405N, National Semiconductor DM7405N, Fairchild 7405PC, Signetics 7405, Motorola MC7405P, AMD AM7405).