MM74HC688MTCX Equivalent & Substitute Parts

Part Overview

The MM74HC688MTCX is an 8-bit magnitude comparator identity logic IC manufactured by onsemi, housed in a 20-TSSOP surface mount package. This device performs equality comparison with active low output (A=B function) and operates across a 2V to 6V supply voltage range. The part is currently listed as obsolete, making equivalent substitute parts necessary for ongoing design support and procurement.

Substiute Parts

MM74HC688MTCX

onsemiIn Stock: 23101MM74HC688MTCX Datasheet

Current PartRFQ

74HC688PW,118

Nexperia USA Inc.In Stock: 347674HC688PW,118 Datasheet

SimilarRFQ

CD74HC688PWR

Texas InstrumentsIn Stock: 2903CD74HC688PWR Datasheet

SimilarRFQ

CD74HC688PWT

Texas InstrumentsIn Stock: 1696CD74HC688PWT Datasheet

SimilarRFQ

SN74HC688PWR

Texas InstrumentsIn Stock: 1913SN74HC688PWR Datasheet

SimilarRFQ

SN74HC688PWT

Texas InstrumentsIn Stock: 1254SN74HC688PWT Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the MM74HC688MTCX is determined by the following critical parameters:

• Device Type: Must be 8-bit identity comparator with active low output (A=B function)
• Package: Must be 20-TSSOP surface mount package
• Supply Voltage: Must support 2V to 6V range
• Output Current: Must support 5.2mA output current capability
• Quiescent Current: Must not exceed 8 µA
• Electrical Compatibility: Propagation delay and operating temperature ranges may vary within acceptable limits for logic substitution

All substitute parts listed maintain identical functional specifications and package geometry, ensuring direct pin-compatible replacement without circuit redesign.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: 74HC688PW,118 (Nexperia USA Inc.)

This part is the preferred substitute due to active product status, ROHS3 compliance, and propagation delay performance (29ns) that exceeds the original specification. The extended operating temperature range (-40°C to 125°C) provides additional design margin. Tape & Reel packaging supports automated assembly processes.

Secondary Recommendation: CD74HC688PWR (Texas Instruments)

This active part offers the widest operating temperature range (-55°C to 125°C) and ROHS3 compliance. Propagation delay of 29ns meets performance requirements. Available in Cut Tape and Digi-Reel packaging formats for flexible procurement.

Alternative Options: SN74HC688PWR (Texas Instruments)

This part maintains active status and ROHS3 compliance with operating temperature range matching the original (-40°C to 85°C). Propagation delay of 36ns remains within acceptable logic substitution tolerances. Available in Cut Tape and Digi-Reel packaging.

Discontinued Parts (Not Recommended for New Designs)

CD74HC688PWT and SN74HC688PWT are listed as discontinued at DiGi Electronics and should not be selected for new production designs despite technical compatibility.

Frequently Asked Questions (FAQ)

Q: Can I directly replace MM74HC688MTCX with any of the listed substitutes?

A: Yes. All listed substitute parts are pin-compatible 8-bit identity comparators in 20-TSSOP packages with identical electrical specifications (supply voltage, output current, quiescent current, and output function). Direct socket replacement is possible without circuit modification.

Q: What is the difference between the Nexperia and Texas Instruments versions?

A: The primary differences are manufacturer, operating temperature range, and propagation delay. Nexperia 74HC688PW,118 and Texas Instruments CD74HC688PWR both offer 29ns propagation delay, while SN74HC688PWR offers 36ns. Texas Instruments CD74HC688PWR supports the widest temperature range (-55°C to 125°C). All meet the original 2V to 6V supply voltage and 5.2mA output current specifications.

Q: Does packaging format affect electrical performance?

A: No. Tape & Reel (TR), Cut Tape (CT), and Digi-Reel packaging formats are logistics variations only. Electrical performance and pin configuration remain identical. Selection should be based on assembly process requirements and procurement volume.

Q: Are all substitutes RoHS compliant?

A: The substitute parts from Texas Instruments and Nexperia are ROHS3 compliant. The original MM74HC688MTCX is listed as REACH Unaffected. All parts carry EAR99 export classification and identical HTSUS codes (8542.39.0001).

Q: Which substitute should I choose for new product designs?

A: For new designs, select from active products only: 74HC688PW,118 (Nexperia) or CD74HC688PWR/SN74HC688PWR (Texas Instruments). Avoid discontinued parts (CD74HC688PWT, SN74HC688PWT). The Nexperia part offers the best balance of performance and availability.

Q: What is the moisture sensitivity level for these parts?

A: All parts, including the original MM74HC688MTCX and all substitutes, have Moisture Sensitivity Level (MSL) of 1 (Unlimited), indicating no moisture sensitivity precautions are required during storage or handling.