74HCT221N,112

Overview

The 74HCT221N,112 is a dual non-retriggerable monostable multivibrator manufactured by Nexperia. It operates within a supply voltage range of 4.5 V to 5.5 V and features TTL-compatible input levels. The device includes Schmitt-trigger action on the nB inputs for improved noise immunity and jitter-free triggering from slow transition rates. Pulse width stability is achieved through internal compensation, remaining virtually independent of VCC and temperature variations. Each multivibrator provides active LOW (nQ) and active HIGH (Q) outputs.

Feature Summary

• Dual non-retriggerable monostable multivibrator configuration with edge-triggered inputs
• Schmitt-trigger action on nB inputs ensures excellent noise immunity
• Internal pulse width compensation maintains stability across voltage and temperature changes
• Direct reset capability allows immediate termination of output pulses

Applications

• Pulse generation circuits requiring stable timing intervals
• Debouncing switches or contacts to eliminate signal bounce
• Timing delays in digital logic sequences

Procurement Notes

Verify that the component matches the specific Nexperia ordering code 74HCT221N,112. Confirm package integrity and pin alignment against the SO16 outline specifications. Ensure compatibility with the required 4.5 V to 5.5 V operating voltage range before integration into the design.

Selection Notes

Select this component when dual independent monostable functions are required within a single package. The HCT logic family ensures direct interfacing with standard TTL logic systems without additional level shifting. Verify that the external timing components meet the specified resistance and capacitance requirements for the desired pulse duration.

Part Context

This device belongs to the 74HCT series of high-speed Si-gate CMOS logic products. It is designed to be pin-compatible with low power Schottky TTL standards while offering CMOS low power dissipation characteristics. The product adheres to JEDEC standard no. 7A specifications for industrial logic integrated circuits.

Replacement Considerations

The 74HC221 serves as a CMOS-level compatible alternative, though it requires different input voltage thresholds compared to the TTL-compatible HCT version. Other monostable multivibrators may require circuit modifications due to differing trigger mechanisms or pin configurations.