SNJ54AHC123AFK

Overview

The SNJ54AHC123AFK is a dual retriggerable monostable multivibrator from the AHC series, manufactured by Texas Instruments. It operates within a supply voltage range of 2V to 5.5V and features Schmitt-trigger circuitry on the A, B, and CLR inputs to accommodate slow input transition rates. The device supports edge triggering from active-high or active-low gated logic inputs and provides glitch-free power-up reset on outputs. It is housed in a 20-pin LCCC package and is rated for an operating temperature range of -55°C to 125°C.

Feature Summary

• Dual retriggerable monostable multivibrators designed for extended output pulse generation
• Schmitt-trigger inputs on A, B, and CLR channels to handle slow transition rates without jitter
• Edge-triggered operation compatible with active-high or active-low gated logic inputs
• Glitch-free power-up reset ensures outputs remain in defined states during initialization

Applications

• Pulse width modulation circuits requiring precise timing control
• Timing delay generation for sequential logic systems
• Debouncing switches or contacts to eliminate signal noise
• Frequency division and pulse stretching applications

Procurement Notes

Verify that the specific part number SNJ54AHC123AFK matches the required 20-pin LCCC package configuration. Confirm the manufacturer is Texas Instruments and check for compliance with MIL-PRF-38535 if military-grade specifications are necessary. Ensure the ordering suffix corresponds to the correct tube packaging quantity and lead finish requirements for your assembly process.

Selection Notes

Select this component when dual independent monostable circuits are needed within a single package. The AHC series offers CMOS compatibility with wide supply voltage flexibility. Verify that external timing components (resistors and capacitors) can be selected to achieve the desired pulse duration using the provided formula. Consider the thermal resistance and package size constraints for your PCB layout.

Part Context

This device belongs to the SN54AHC123A family of dual retriggerable monostable multivibrators. The 'SNJ' prefix indicates a ceramic DIP or LCCC package variant suitable for high-reliability applications. The 'FK' suffix specifically denotes the 20-pin LCCC package type. This family is part of Texas Instruments' broader AHC logic line, designed for low power consumption and high-speed performance.

Replacement Considerations

Public confirmed substitute part numbers include SNJ54AHC123AJ (16-pin CDIP) and SNJ54AHC123AW (16-pin CFP). These variants share identical electrical characteristics but differ in pin count and physical package dimensions. Verify pinout compatibility and mechanical fit before substitution.