SN54HC688J

Comparators Overview

The SN54HC688J is an 8-bit identity comparator from Texas Instruments, designed for military-grade applications. It operates within a supply voltage range of 2 V to 6 V and features active-low outputs that indicate equality between two 8-bit binary words. The device utilizes a 20-lead ceramic dual in-line package (CDIP) suitable for high-reliability environments. Key electrical specifications include a maximum propagation delay of 26 ns at 6 V and 45 ns at 2 V, with a maximum quiescent current of 80 µA. It supports an extended operating temperature range from -55°C to +125°C.

Comparators Feature Summary

• Provides 8-bit identity comparison functionality with active-low output indication when input words are equal.
• Constructed with CMOS technology for low power consumption and high noise immunity.
• Engineered for military-grade reliability with a robust ceramic dual in-line package (CDIP).
• Capable of operation across a wide supply voltage range and extreme temperature conditions.

Comparators Applications

• Military avionics systems requiring high-reliability logic components
• Spacecraft data processing and telemetry control circuits
• Industrial automation controllers operating in harsh environmental conditions

Comparators Procurement Notes

Verify the specific suffix J indicates the ceramic DIP package and mil-spec qualification. Confirm RoHS status as military parts may differ from commercial standards. Ensure the supplier provides traceability documentation required for defense or aerospace procurement. Check for lead-free plating options if required by specific project constraints. Validate the operating temperature range matches the intended application environment.

Comparators Selection Notes

Select this component when military-grade reliability and radiation hardness are required compared to commercial SN74HC688 variants. Consider the CDIP package for through-hole mounting in ruggedized enclosures. Evaluate the 2V to 6V supply range compatibility with existing system power rails. Assess the propagation delay requirements against system timing budgets. Verify that the 8-bit width meets the specific data comparison needs of the design.

Comparators Part Context

This part belongs to the SN54HC series of high-speed CMOS logic devices manufactured by Texas Instruments. The SN54 series is distinguished from the SN74 series by its wider temperature range and stricter manufacturing controls for military and aerospace use. It serves as a specialized version of the standard HC logic family, ensuring performance stability under extreme thermal and mechanical stress conditions found in defense applications.

Comparators Replacement Considerations

The SN74HC688DRE4 is a commercial equivalent but lacks the military-grade temperature range and packaging. Direct substitution requires verifying that the commercial grade meets the environmental requirements of the specific application. No other direct pin-compatible military alternatives are documented in the provided source material.