74HC688N,652

Overview

The NXP USA Inc. 74HC688N,652 is an obsolete 8-bit magnitude comparator integrated circuit manufactured by NXP Semiconductors. It operates within a supply voltage range of 2 V to 6 V and features active low outputs for equality detection (A=B). The device utilizes a 20-pin DIP package and supports surface mount or through-hole installation. Key electrical parameters include a maximum propagation delay of 170 ns and a maximum supply current of 8 µA. Operating temperatures range from -40 °C to +125 °C.

Feature Summary

• Performs 8-bit magnitude comparison between two binary or BCD words
• Provides active low output signals indicating logical equality conditions
• Compatible with low power Schottky TTL (LSTTL) pin configurations

Applications

• Digital logic circuits requiring 8-bit data word comparison
• System monitoring for address matching or value verification
• Embedded control systems utilizing CMOS logic families

Procurement Notes

This component is officially listed as obsolete and no longer manufactured by NXP. Availability is restricted to surplus or secondary market channels. Verify authenticity and storage history carefully when sourcing from non-authorized distributors. Ensure replacement strategies are evaluated due to discontinuation status.

Selection Notes

Select this part only if legacy compatibility with LSTTL interfaces is required. Consider the 20-pin DIP form factor for existing board layouts. Evaluate alternative modern comparators if new designs are permitted, as the 74HC688 series is discontinued. Confirm voltage tolerance matches the 2V–6V operational range.

Part Context

The 74HC688 belongs to the standard 74HC logic family, designed for high-speed CMOS applications. It serves as a specialized comparator rather than a general-purpose gate. The 'N' suffix indicates the specific 20-pin dual in-line package variant. This component type is foundational in digital electronics for direct binary value evaluation tasks.

Replacement Considerations

Publicly confirmed substitute part numbers are not explicitly listed in the provided documentation. Users should consult official NXP substitution guides or equivalent industry-standard 8-bit magnitude comparators for valid replacements.