MM74HC423AN

Overview

The MM74HC423AN is a dual retriggerable monostable multivibrator from the HC logic family, housed in a 16-lead Plastic Dual-In-Line (PDIP) package. It operates within a supply voltage range of 2V to 6V and supports an operating temperature range of -40°C to +85°C. The device features Schmitt Trigger inputs for slow rise/fall times up to one second. Key electrical parameters include a maximum quiescent current of 80 µA, a typical propagation delay of 40 ns, and a fanout of 10 LS-TTL loads. Pulse width is determined by external RC components.

Feature Summary

• Dual retriggerable monostable multivibrator architecture with independent timing circuits
• Schmitt Trigger A and B inputs accommodate slow signal transitions
• Linear CMOS techniques ensure pulse width stability across wide temperature and supply variations
• Outputs can be reset during generation via the Clear input

Applications

• Pulse generation and shaping
• Timing delays
• Debouncing switches
• Frequency division

Procurement Notes

Verify the specific ordering suffix 'N' corresponds to the 16-lead PDIP package as documented in the datasheet. Confirm that the component meets the required industrial temperature specifications (-40°C to +85°C). Ensure external timing components are selected to maintain pulse width variation within the specified ±5% tolerance. Check for any end-of-life or obsolescence notices from the manufacturer before finalizing procurement plans.

Selection Notes

Select this component when a dual-channel retriggerable monostable circuit is required in a through-hole DIP package. It is suitable for applications needing high noise immunity and low power consumption characteristic of CMOS technology. Consider the 40 ns typical propagation delay and the ability to handle slow input transitions due to Schmitt Trigger inputs. Verify that the external RC network can support the desired pulse width range without exceeding the minimum resistor constraints defined in the datasheet.

Part Context

This part belongs to the MM74HC423A series of dual retriggerable monostable multivibrators manufactured by onsemi (formerly Fairchild Semiconductor). The 'N' suffix specifically denotes the 16-lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001 standard. The series utilizes advanced silicon-gate CMOS technology to achieve speeds comparable to Low Power Schottky TTL while retaining CMOS low power benefits.

Replacement Considerations

Cross-reference tools indicate functional equivalents may exist from other manufacturers, but verification against the official datasheet is required. Ensure substitute parts match the 16-pin PDIP footprint and HC logic family electrical characteristics. Confirm pin compatibility, particularly regarding the Clear input and timing pins, to avoid redesigning the PCB layout.