74HCT221DB,112

Overview

The 74HCT221DB,112 is a dual non-retriggerable monostable multivibrator manufactured by NXP Semiconductors. It belongs to the HCT logic family and operates within a standard voltage range compatible with TTL inputs. The device features two independent circuits, each equipped with active LOW-going edge input (nA) and active HIGH-going edge input (nB). These inputs can function as enable signals for pulse generation. An overriding reset input allows termination of the output pulse before completion. The component utilizes an external resistor and capacitor network to set the timing duration.

Feature Summary

• Dual independent non-retriggerable monostable multivibrator configuration
• Active LOW-going edge input (nA) and active HIGH-going edge input (nB)
• Overriding reset capability to terminate output pulses
• External RC timing control for pulse width adjustment

Applications

• Pulse generation and shaping in digital systems
• Timing delay circuits requiring precise duration control
• Debouncing switches or contacts in microcontroller interfaces
• One-shot triggering for sequential logic operations

Procurement Notes

Verify the specific suffix '112' against current NXP documentation to confirm package type and compliance status. Check for End-of-Life notices or Product Change Notifications that may affect availability. Ensure the SSOP-16 package matches your PCB footprint requirements. Confirm RoHS compliance details if required for your manufacturing process.

Selection Notes

Select this component when dual independent one-shot timers are needed with TTL-compatible inputs. The HCT series ensures compatibility with 5V CMOS logic families. Consider the external RC components for timing accuracy. Verify that the non-retriggerable nature meets your application's timing constraints compared to retriggerable alternatives like the 74HCT123.

Part Context

This part is part of the 74HCT221 series, which includes variants such as 74HCT221D. It is designed for high-speed Si-gate CMOS technology and is pin-compatible with low power Schottky TTL standards. The device complies with JEDEC standard no. 7A. It is suitable for applications requiring reliable monostable operation with noise-immune inputs.

Replacement Considerations

Check for direct replacements like 74HCT221D from NXP. Other manufacturers may offer equivalent parts, but verify pinout and electrical characteristics carefully.