SN74HC688DWR

Overview

The SN74HC688DWR is an 8-bit identity comparator from Texas Instruments' SN74HC series, housed in a 20-pin SOIC package. It performs comparisons of two 8-bit binary or BCD words, providing an active-low output when inputs A and B are equal. The device operates within a supply voltage range of 2 V to 6 V and supports surface-mount installation. Key electrical parameters include a propagation delay of 36 ns at 6 V with 50 pF load, static current of 8 µA, and output currents of ±5.2 mA. It functions reliably across an operating temperature range of -40°C to +85°C.

Feature Summary

• Performs 8-bit identity comparison between two binary or BCD words
• Provides active-low output signal when input values are identical
• Includes output-enable input for controlling output state

Applications

• Digital data validation systems
• Memory address matching circuits
• Control logic equality checks

Procurement Notes

Verify the specific ordering suffix G4 indicates lead-free and RoHS compliance status as per manufacturer documentation. Confirm the SOIC-20 package dimensions match your PCB footprint requirements. Ensure the operating voltage range aligns with your system's power supply rails. Check the latest datasheet for any pinout revisions or environmental certification updates before finalizing procurement specifications.

Selection Notes

Select this component when an 8-bit equality check is required in HC-speed logic applications. The wide 2 V to 6 V supply range offers flexibility for various digital systems. Consider the 36 ns propagation delay for timing constraints. The SOIC-20 package provides a balance of pin count and board space. Verify that the active-low output polarity suits your downstream logic interface requirements.

Part Context

This part belongs to the SN74HC688 family of 8-bit identity comparators. It shares functional similarities with other members like SN74HC688PWRE4 but differs in packaging. The SN74HC series ensures compatibility with standard CMOS logic levels while offering improved speed over older variants. It serves as a core component for digital comparison tasks in industrial and consumer electronics.

Replacement Considerations

SN74HC688PWRE4 is a verified alternative in TSSOP-20 packaging. SN74ALS688DWR offers faster performance but requires a stricter 5 V supply. Verify pin compatibility and thermal characteristics when substituting.