CD54HCT123F3A

The CD54HCT123F3A is a military-grade high-speed CMOS dual retriggerable monostable multivibrator with reset from Texas Instruments, part of the 54HCT logic family in a ceramic DIP (CDIP) package. It integrates two independent monostable circuits, each producing output pulse widths defined by external timing resistor and capacitor components. The TTL-compatible inputs accept both positive- and negative-edge triggers, while an active-low reset input allows immediate pulse termination at any point. Retriggering capability extends the output pulse when successive triggers occur, supporting long-duration timing sequences and missing-pulse detection. Operation is guaranteed across the full military temperature range of -55 °C to +125 °C, and the hermetic ceramic package delivers robust noise margins and resistance to moisture and thermal stress.

Typical deployments include precision one-shot timing, pulse shaping, frequency division, and watchdog timer functions in avionics, radar processing, missile guidance, satellite communications, and ruggedized industrial controllers. The dual-channel architecture helps minimize component count in sequential logic designs requiring compact timing solutions. For procurement and sustainment, the 54-series prefix confirms military temperature ratings and controlled baseline manufacturing suitable for long-life defense and aerospace programs. However, as with many mature ceramic-packaged logic products, the CD54HCT123F3A may be subject to lifecycle transitions and constrained availability. Engineering teams should validate current obsolescence status and rely on authorized distribution channels to ensure traceability and form‑fit‑function compatibility when maintaining legacy systems or designing for extended‑duration high‑reliability environments.