SN74HC688PWR

Overview

The SN74HC688PWR is an 8-bit identity comparator from Texas Instruments, designed to verify equality between two 8-bit binary words. It operates within a wide supply voltage range of 2 V to 6 V and features active-low outputs that assert when input A equals input B. The device utilizes a TSSOP-20 surface-mount package and supports propagation delays as low as 36 ns at 5 V. It offers high-current outputs capable of driving up to 10 LSTTL loads while maintaining low power consumption with a maximum quiescent current of 80 μA.

Feature Summary

• Performs 8-bit identity comparison by asserting output only when both input vectors are identical
• Provides active-low logic outputs for direct interfacing with standard digital systems
• Delivers high-current drive capability suitable for loading multiple LSTTL inputs
• Ensures low static power consumption through optimized CMOS design

Applications

• Digital data validation circuits requiring word-level equality checks
• Memory address decoding and verification systems
• Control logic for detecting specific binary states in microprocessor interfaces
• Error detection modules in communication protocols

Procurement Notes

Verify the component marking and date code against the manufacturer's production data sheet to confirm authenticity. Ensure the TSSOP-20 package matches your PCB footprint requirements. Check for RoHS compliance documentation if environmental regulations apply to your assembly process. Confirm that the operating temperature range meets your system's thermal specifications.

Selection Notes

Select this component when an 8-bit magnitude comparison is required with active-low output signaling. The TSSOP-20 package is suitable for space-constrained designs needing surface-mount technology. Consider the 2 V to 6 V operating range for compatibility with various logic families. Evaluate the propagation delay specifications against your system's timing constraints to ensure signal integrity.

Part Context

This part belongs to the SN74HC688 series of 8-bit identity comparators manufactured by Texas Instruments. It is part of the broader HC (High-speed CMOS) logic family, which provides performance comparable to LS-TTL but with lower power consumption. The device is designed for general-purpose digital applications requiring reliable binary comparison functionality.

Replacement Considerations

The SN74HC688DWRG4 serves as a pin-compatible alternative in an SOIC-20 package. Verify package dimensions and thermal characteristics before substitution. Cross-reference datasheets to ensure equivalent electrical parameters and logic functions match your design requirements.