74HCT688D,653 Equivalent & Substitute Parts

Part Overview

The 74HCT688D,653 is an 8-bit identity comparator manufactured by NXP USA Inc., designed for magnitude comparison applications with active low output. This device is classified as obsolete, which necessitates identification of functionally equivalent alternatives for ongoing design support and procurement continuity. The part operates within the 74HCT logic family standard, providing reliable comparison functionality across industrial and commercial temperature ranges.

Substiute Parts

74HCT688D,653

NXP USA Inc.In Stock: 95674HCT688D,653 Datasheet

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CD74HCT688M96

Texas InstrumentsIn Stock: 2969CD74HCT688M96 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the 74HCT688D,653 is based on strict equivalence of the following critical parameters:

• Functional Identity: 8-bit identity comparator with A=B output function
• Logic Family: 74HCT series compatibility
• Output Configuration: Active low output
• Electrical Specifications: Supply voltage 4.5V ~ 5.5V, output current 4mA, propagation delay 34ns @ 4.5V with 50pF load, quiescent current 8 µA
• Package Compatibility: 20-SOIC surface mount package (0.295", 7.50mm width)
• Compliance Requirements: ROHS3 compliant, MSL Level 1

The CD74HCT688M96 manufactured by Texas Instruments meets all substitution criteria while offering active product status and extended operating temperature range.

Parameter Comparison

Engineering Selection Recommendations

The CD74HCT688M96 from Texas Instruments is a direct functional equivalent to the 74HCT688D,653. Both devices maintain identical electrical performance specifications and package configuration. The primary advantage of the CD74HCT688M96 is its active product status, ensuring long-term availability and supply chain continuity. The extended operating temperature range of -55°C to 125°C provides additional margin for applications requiring lower temperature operation. Both parts maintain full ROHS3 compliance and MSL Level 1 rating, supporting equivalent environmental and reliability standards.

Frequently Asked Questions (FAQ)

Q: Can the CD74HCT688M96 be used as a direct replacement for the 74HCT688D,653?

A: Yes. Both devices are 8-bit identity comparators with identical electrical specifications, output configuration, supply voltage requirements, propagation delay, and 20-SOIC package dimensions. Pin-for-pin compatibility is maintained.

Q: What is the difference in operating temperature range?

A: The 74HCT688D,653 operates from -40°C to 125°C, while the CD74HCT688M96 operates from -55°C to 125°C. The extended lower temperature range of the Texas Instruments device provides additional operational margin for applications requiring sub-zero temperature performance.

Q: Are both parts RoHS compliant?

A: Yes. Both the 74HCT688D,653 and CD74HCT688M96 are ROHS3 compliant with MSL Level 1 rating, meeting equivalent environmental and regulatory requirements.

Q: Why is the NXP part listed as obsolete?

A: The 74HCT688D,653 has reached end-of-life status with NXP. The CD74HCT688M96 remains in active production by Texas Instruments, providing continued availability for new designs and replacement applications.

Q: Are there any package or mounting differences?

A: No. Both devices use the 20-SOIC surface mount package with identical 0.295" (7.50mm) width specifications. PCB footprints and assembly processes remain unchanged.