74HCT221D,118

Overview

The Nexperia 74HCT221D,118 is a dual non-retriggerable monostable multivibrator housed in an SO16 (SOT109-1) package. It operates within a supply voltage range of 4.5 V to 5.5 V and supports ambient temperatures from -40 °C to +125 °C. The device features TTL input levels with Schmitt-trigger action on the nB inputs for noise immunity. Pulse width is determined by external timing components using the relationship tW = 0.7 × CEXTREXT. Propagation delays from trigger inputs to outputs typically range from 21 ns to 44 ns at 4.5 V.

Feature Summary

• Dual non-retriggerable monostable multivibrator configuration
• Schmitt-trigger action on nB inputs for jitter-free triggering
• Direct active LOW reset capability to terminate output pulses
• CMOS low power dissipation with high noise immunity

Applications

• Pulse generation circuits
• Timing delay applications
• Debouncing switches
• Frequency division

Procurement Notes

Verify the specific ordering suffix '118' corresponds to the standard tape-and-reel packaging format required for automated assembly processes. Confirm that the SO16 plastic small outline package dimensions align with the target PCB footprint constraints. Ensure the selected component meets the required RoHS compliance standards for the intended manufacturing environment.

Selection Notes

Select this component when dual independent monostable circuits are required within a single package. The HCT logic family ensures compatibility with TTL-level control signals. Verify that the external resistor and capacitor values can achieve the desired pulse width stability, as internal compensation makes the output virtually independent of supply voltage variations.

Part Context

This part belongs to the 74HCT series of high-speed CMOS logic devices manufactured by Nexperia. It provides dual monostable functionality within a standard 16-lead small outline package. The device is designed for general-purpose digital applications requiring precise timing intervals controlled by external passive components.

Replacement Considerations

Check for other 74HCT221 variants with different package options or suffixes if lead availability is constrained. Ensure any substitute maintains the same SO16 pinout and electrical characteristics to guarantee direct interchangeability without circuit redesign.