SN74AHCT123ANE4

Overview

The SN74AHCT123ANE4 is a dual retriggerable monostable multivibrator from the AHCT logic family. It operates within a supply voltage range of 4.5 V to 5.5 V and supports an operating temperature range of -40°C to +85°C. The device features Schmitt-trigger inputs on A, B, and CLR channels for jitter-free triggering with slow transition rates. Propagation delay ranges from 1 ns to 15 ns depending on load conditions. Output drive capability reaches ±8 mA at VCC = 5 V.

Feature Summary

• TTL-voltage compatible CMOS inputs designed for direct interfacing with TTL logic devices
• Schmitt-trigger circuitry on all control inputs provides tolerance to slow or noisy input signals
• Retriggerable architecture allows extension of output pulse duration by subsequent trigger events
• Clear (CLR) input overrides trigger functions to terminate output pulses early

Applications

• Pulse width generation and timing circuits
• Debouncing switches and contacts
• Frequency division and pulse stretching
• Timing delays in digital systems

Procurement Notes

Verify that the ordering suffix 'E4' corresponds to lead-free manufacturing and RoHS compliance as specified by Texas Instruments. Confirm the package type matches the required PCB footprint, typically PDIP-16 for this suffix variant. Ensure the application environment remains within the recommended operating temperature range of -40°C to +85°C to maintain electrical specifications.

Selection Notes

Select this component when TTL-level compatibility is required alongside CMOS low power consumption. The AHCT series bridges the gap between older TTL standards and modern CMOS processes. Verify that external timing components can handle the required pulse durations and that the supply voltage strictly adheres to the 4.5 V to 5.5 V range for proper logic threshold operation.

Part Context

This device belongs to the SNx4AHCT123A family of dual retriggerable monostable multivibrators. It shares functional characteristics with other members of the AHCT family but is distinguished by its specific TTL-compatible input thresholds and packaging options. The 'N' package designation indicates a Plastic Dual In-Line Package suitable through-hole mounting.

Replacement Considerations

SN74AHCT123AN

FAQ

How does the device handle slow input transitions?

The A, B, and CLR inputs feature Schmitt-trigger circuitry which provides hysteresis, allowing the device to trigger cleanly without jitter even with slow input transition rates.

What is the function of the CLR input?

The Clear (CLR) input overrides the A and B trigger inputs. Driving CLR high terminates the current output pulse immediately, reducing the pulse duration.