SNJ54LS74AJ

The SNJ54LS74AJ is a dual D-type positive-edge-triggered flip-flop with asynchronous preset and clear functions, manufactured by Texas Instruments as part of the 54LS low-power Schottky TTL logic family. Housed in a ceramic dual in-line package (CDIP), the device offers hermetic sealing for reliable operation in severe environmental conditions. Each flip-flop accepts a single data input and a clock signal, transferring the input state to the complementary Q and Q̅ outputs on the rising edge of the clock. Independent preset and clear inputs allow asynchronous initialization, overriding the clock. The circuit is characterized over the full military temperature range of -55°C to +125°C and operates from a 5 V supply with standard TTL input thresholds. Its low-power Schottky design balances moderate switching speed with reduced power dissipation compared to standard TTL.

Typical applications span defense avionics, space-qualified subsystems, and industrial control systems that demand high-reliability logic elements. The flip-flop serves as a basic building block in state machines, shift registers, frequency dividers, and synchronous data storage buffers within mission-critical embedded platforms. The SNJ54LS74AJ’s military-grade prefix and ceramic packaging indicate compliance with rigorous screening and qualification requirements, often referencing MIL-STD-883 or equivalent standards. As a mature logic device, it remains in production for legacy support programs; however, supply chain planning should account for potential extended lead times and the need for certified distributors to mitigate counterfeit risk. Design engineers typically select this part when continuity with existing 5V TTL designs, rugged packaging, and long-term availability are paramount.