SN74AHC123APWRE4

Overview

The SN74AHC123APWRE4 is a dual retriggerable monostable multivibrator from the Texas Instruments AHC logic series, housed in a 16-pin TSSOP package. It operates within a supply voltage range of 2 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 terminals to accommodate slow transition rates. Output pulse duration is externally programmable via resistance and capacitance connected to Rext/Cext and Cext pins.

Feature Summary

• Dual edge-triggered monostable multivibrators with independent timing control for each circuit
• Retriggerable architecture allows extension of output pulse duration through subsequent input triggers
• Schmitt-trigger circuitry on all inputs ensures jitter-free triggering with slow signal transitions
• Glitch-free power-up reset maintains outputs in defined states during initial power application

Applications

• Pulse generation and timing circuits requiring precise external RC control
• Debouncing switches or contacts to eliminate mechanical bounce noise
• One-shot pulse width modulation for signal conditioning
• Frequency division and pulse stretching in digital systems

Procurement Notes

Verify component authenticity by checking the manufacturer marking HA123A on the top surface. Confirm the PWRE4 suffix corresponds to the TSSOP-16 tape and reel packaging format. Ensure the order matches the specific SN74AHC123APWRE4 designation to guarantee correct voltage and temperature ratings.

Selection Notes

Select this component when dual independent monostable functions are required in a compact surface-mount footprint. The AHC series offers high-speed performance compatible with standard CMOS logic levels. Verify that external timing components support the desired pulse width calculations and that the operating environment stays within the specified -40°C to +85°C thermal range.

Part Context

This part belongs to the SN74AHC123A family of dual retriggerable monostable multivibrators. The 'A' variant denotes enhanced specifications compared to standard versions. The PWRE4 suffix indicates the specific TSSOP-16 package configuration with lead-free RoHS compliance and tape-and-reel shipping method for automated assembly processes.

Replacement Considerations

SN74AHC123APWR

FAQ

How is the output pulse duration determined?

The pulse duration is programmed using external resistance and capacitance values connected to the Rext/Cext and Cext terminals.

What happens if the CLR input is activated?

Activating the Clear (CLR) input overrides the A or B inputs and terminates the output pulse immediately.