74VHC123AN

Overview

The Fairchild Semiconductor 74VHC123AN is a dual monostable multivibrator integrated circuit manufactured using advanced silicon gate CMOS technology. It operates within a supply voltage range of 2 V to 5.5 V and features a typical propagation delay of 8.1 ns at 25°C. The device provides complementary outputs with high noise immunity, defined as 28% of VCC minimum for both high and low states. It includes Schmitt trigger inputs on the negative A and positive B terminals to tolerate slow input transitions. The component is housed in a 16-pin PDIP package and supports operation across an industrial temperature range of -40°C to +85°C.

Feature Summary

• Dual monostable multivibrator architecture utilizing advanced silicon gate CMOS technology for high-speed performance combined with low power consumption.
• Integrated Schmitt trigger functionality on all inputs to ensure reliable triggering despite slow rise and fall times on input signals.
• Complementary output configuration providing both true and inverted pulse signals for flexible circuit integration.
• Robust input protection circuits allowing application of voltages up to 7 V regardless of the supply voltage level.

Applications

• Timing generation and pulse width modulation circuits
• Debouncing switches and push-button interfaces
• Frequency division and pulse stretching applications

Procurement Notes

Verify the specific manufacturer origin, as this part number was historically produced by Fairchild Semiconductor prior to its acquisition by onsemi. Confirm that the received component matches the original Fairchild specifications regarding pinout compatibility and electrical characteristics. Ensure the package type corresponds to the standard 16-PDIP format. Check for any process change notifications or obsolescence notices related to the legacy Fairchild production line before finalizing procurement plans.

Selection Notes

Select this component when a dual-channel monostable solution is required with fast switching speeds and low quiescent current. It serves as a direct pin-compatible upgrade for older 74HC123 designs, offering improved speed without increasing power dissipation. Consider the 2 V to 5.5 V operating range for systems requiring flexibility between lower voltage logic levels and standard 5 V environments. Verify that the through-hole PDIP packaging aligns with the target PCB design constraints.

Part Context

The 74VHC123AN belongs to the 74VHC series of high-speed CMOS logic devices. This series bridges the performance gap between standard HC logic and faster LVCMOS technologies while maintaining backward compatibility with TTL logic levels. The device integrates two independent monostable multivibrators into a single package, optimizing board space for timing-critical applications. Its design emphasizes noise tolerance and signal integrity in mixed-signal environments.

Replacement Considerations

Direct substitutes include the SN74AHC123AN from Texas Instruments. Other compatible alternatives within the same logic family may be sourced from manufacturers such as onsemi or Nexperia, provided they maintain identical pin configurations and electrical parameters.