SN74LS123DR Dual Retriggerable Monostable Multivibrator – SOIC-16

Description

The SN74LS123DR is a dual retriggerable monostable multivibrator that utilizes Low-power Schottky (LS) TTL technology. Each of the two multivibrators provides stable pulse generation, with the output pulse width determined by an external resistor (R) and capacitor (C) network. Being “retriggerable” means that if a new trigger signal is received while an output pulse is already active, the timing cycle can be extended, making it highly effective for watchdog timers and pulse-stretching applications.

The device offers flexible control via dedicated trigger inputs (active-HIGH and active-LOW) and a direct-reset input that can immediately terminate the output pulse. This configuration is widely used in digital systems for generating precise time delays, debouncing mechanical switches, and signal conditioning.

Note: Product images are for illustrative purposes only. Since this IC relies on an external RC network to determine pulse duration, please consult the official Texas Instruments datasheet for the timing equations, recommended component ranges, and pin-configuration details.

Features

• Dual Multivibrator: Two independent monostable timing circuits in a single 16-pin package.
• Retriggerable Design: Allows for the extension of the output pulse width with subsequent trigger inputs.
• Flexible Triggering: Features both active-HIGH and active-LOW trigger inputs for circuit versatility.
• Direct Reset: Overriding active-LOW reset input allows for immediate pulse termination.
• LS-TTL Compatible: Engineered with Low-power Schottky technology for reliable performance within standard TTL logic systems.
• Package: SOIC-16 (SMD) for standard surface-mount assembly.

Benefits

• Timing Precision: Provides a stable and repeatable method for generating pulses of controlled duration.
• Design Versatility: The combination of retriggerable operation and direct reset allows for complex pulse shaping and sequence control.
• Space-Saving: Dual-channel integration effectively doubles the timing capability while occupying a minimal PCB footprint.

Applications

• Watchdog Timers: Ensuring system health by resetting logic if a periodic signal is missed.
• Switch Debouncing: Cleaning up noisy mechanical switch inputs to produce a single, stable logic pulse.
• Pulse Shaping/Delay: Creating precise time delays or adjusting the duty cycle of digital signals.
• Control Systems: Useful in automated sequences where specific events need to be triggered after a defined time interval.

Package Includes

• 1 x SN74LS123DR Dual Retriggerable Monostable Multivibrator IC (SMD-16)

Specifications