74HC688DB,112

Overview

The 74HC688DB,112 is an 8-bit magnitude comparator manufactured by Nexperia USA Inc. It operates within a supply voltage range of 2V to 6V and features active-low outputs for A=B comparison. The device is housed in a 20-pin SSOP package with a maximum propagation delay of 29 ns. It supports a wide operating temperature range from -40°C to +125°C and includes input clamp diodes.

Feature Summary

• Performs identity comparisons between two 8-bit binary or BCD words
• Provides active-low output signals when input values are equal
• Incorporates input clamp diodes for enhanced noise immunity

Applications

• Digital data validation systems
• Address matching circuits
• Error detection logic in microprocessor interfaces

Procurement Notes

This component is officially classified as obsolete and is no longer manufactured by Nexperia. Distributors may list limited remaining stock, but new production orders are not accepted. Verification of authenticity and storage history is critical due to the end-of-life status. Buyers should confirm the specific revision level and physical condition before acquisition.

Selection Notes

Engineers requiring this functionality must evaluate alternative components due to the part's discontinued status. Selection criteria should focus on pin-compatible replacements that maintain the 8-bit identity comparison capability and similar electrical characteristics. Compatibility with existing PCB footprints and signal integrity requirements must be verified against substitute datasheets.

Part Context

The 74HC688 belongs to the standard 74HC series of high-speed CMOS logic devices. This specific model implements magnitude comparison logic rather than arithmetic operations. It is designed for general-purpose digital applications requiring reliable equality checking between parallel data buses in industrial and consumer electronics environments.

Replacement Considerations

Public confirmed substitutes include the 74HCT688DB,112 for TTL-compatible logic levels. Designers should verify voltage compatibility and package dimensions when transitioning to these alternatives.