74HCT688D,653

Comparators Overview

The NXP USA Inc. 74HCT688D,653 is an 8-bit magnitude comparator belonging to the 74HCT series of high-speed Si-gate CMOS devices. It operates within a supply voltage range of 4.5 V to 5.5 V and features active low outputs. The component is housed in a 20-SOIC package with a width of 7.50 mm. It supports a minimum operating temperature of -40°C and a maximum of +125°C. Propagation delays are specified at 170 ns, 34 ns, and 29 ns under various conditions, with a maximum power supply current of 8 µA.

Comparators Feature Summary

• Performs identity comparison logic where outputs indicate equality between input data words
• Compatible with low power Schottky TTL (LSTTL) logic levels for seamless integration
• Utilizes high-speed Si-gate CMOS technology for efficient performance

Comparators Applications

• Digital systems requiring precise magnitude comparison of 8-bit data words
• Integration into circuits designed for LSTTL compatibility
• Industrial control applications operating within extended temperature ranges

Comparators Procurement Notes

This component is scheduled for obsolescence and will be discontinued by the manufacturer. Verify availability through authorized distributors or consider alternative packages. Ensure compliance with RoHS and REACH directives as applicable to your region. Confirm lead times and substitute options early due to end-of-life status.

Comparators Selection Notes

Select this part when an 8-bit magnitude comparator with HCT logic levels is required. It serves as a direct replacement for HC variants in LSTTL-compatible designs. Consider the 20-SOIC package constraints and thermal specifications. Verify that the active low output polarity meets system requirements before finalizing the design.

Comparators Part Context

The 74HCT688D,653 is part of the broader 74HCT688 family, which includes variants like the 74HC688PW-T. While sharing functional similarities, differences exist in speed and voltage tolerance between HC and HCT series. This specific D,653 suffix denotes the SOIC package and manufacturing lot details from Nexperia/NXP.

Comparators Replacement Considerations

Public confirmed substitutes include CD74HCT163M from Texas Instruments, though this is a counter IC and not a direct functional equivalent. Users should verify pin-to-pin compatibility and logical equivalence carefully. No direct 8-bit comparator substitute is explicitly listed in the provided public data.