The 74HC123N,652 from NXP Semiconductors is a high-speed Si-gate CMOS device that functions as a dual retriggerable monostable multivibrator with reset. This component is notable for its ability to control output pulse width through three primary methods: selection of external resistor and capacitor, retriggering through gated active low-going or high-going edge inputs, and direct reset to terminate the output pulse.
Schmitt-trigger action on all inputs except for the reset input enhances the device's tolerance to slower input rise and fall times, making it highly adaptable to various signal conditions. The device is pin compatible with Low-power Schottky TTL (LSTTL) and complies with JEDEC standard no. 7A, ensuring broad compatibility and ease of integration into existing designs.
Integrated Circuits (ICs)
Monostable multivibrators, or 'one-shots', are a type of digital circuit used to generate a single output pulse of a specified duration in response to an input trigger. Dual retriggerable monostable multivibrators, such as the 74HC123N,652, offer enhanced functionality by allowing the pulse duration to be extended through retriggering, making them versatile components for timing, pulse generation, and sequential logic applications.
When selecting a monostable multivibrator for a design, engineers should consider factors such as the desired pulse width, retriggering capabilities, and compatibility with existing logic levels. The choice of external resistor and capacitor values directly influences the pulse width, offering flexibility in adjusting the timing characteristics to meet specific design requirements.
The ability to directly reset the output pulse and the inclusion of Schmitt-trigger action on inputs further enhance the component's utility by providing precise control over pulse timing and improving tolerance to varying input signal conditions. Additionally, compatibility with both CMOS and LSTTL logic levels ensures that these devices can be easily integrated into a wide range of digital systems.