74HCT85D,652 Magnitude Comparator - Equivalent & Substitute Parts

Part Overview

The 74HCT85D,652 is a 4-bit magnitude comparator manufactured by Nexperia USA Inc., designed to perform binary comparison operations with active high outputs for A<B, A=B, and A>B functions. This component is classified as obsolete, making equivalent substitute parts necessary for ongoing design support and procurement continuity. The 74HCT series provides TTL-compatible logic operation within the 4.5V to 5.5V supply voltage range, suitable for digital comparison applications requiring standard propagation delay performance.

Substiute Parts

74HCT85D,652

Nexperia USA Inc.In Stock: 121174HCT85D,652 Datasheet

Current PartRFQ

CD74HCT85M

Texas InstrumentsIn Stock: 1248CD74HCT85M Datasheet

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CD74HCT85M96

Texas InstrumentsIn Stock: 795CD74HCT85M96 Datasheet

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CD74HCT85MT

Texas InstrumentsIn Stock: 1454CD74HCT85MT Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 74HCT85D,652 are qualified based on the following critical parameters that determine functional and mechanical compatibility:

Substitution Criteria:

• Type: Magnitude Comparator (4-bit)
• Output Configuration: Active High with A<B, A=B, A>B functions
• Voltage Supply Range: 4.5V ~ 5.5V
• Output Current Capability: 4mA High, 4mA Low
• Package: 16-SOIC form factor (0.154", 3.90mm Width)
• Mounting: Surface Mount
• Series Compatibility: 74HCT logic family
• Compliance: ROHS3 Compliant, REACH Unaffected

All substitute parts listed maintain identical electrical specifications for supply voltage, output current, quiescent current, and functional output behavior. Propagation delay variations and operating temperature ranges are noted but do not preclude substitution within standard design margins.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute Recommendations:

CD74HCT85M and CD74HCT85MT (Texas Instruments) are the preferred substitutes for the obsolete 74HCT85D,652. Both parts are manufactured by Texas Instruments, maintain active product status, and provide identical electrical performance within the 74HCT logic family. The CD74HCT85M is supplied in tube packaging, while the CD74HCT85MT is supplied in tape and reel format for automated assembly operations. Both variants demonstrate improved propagation delay performance (40ns versus 44ns) and extended lower operating temperature range (-55°C versus -40°C), providing enhanced design margin.

Secondary Substitute:

CD74HCT85M96 (Texas Instruments) is functionally equivalent but carries discontinued status at DiGi Electronics, limiting long-term procurement viability. This part should be considered only when primary substitutes are unavailable.

Compliance Basis:

All substitute parts maintain ROHS3 compliance, REACH unaffected status, and identical moisture sensitivity classification (MSL 1), ensuring regulatory and environmental compatibility with the original design specification.

Frequently Asked Questions (FAQ)

Q: Can the CD74HCT85M directly replace the 74HCT85D,652 without circuit modification?

A: Yes. The CD74HCT85M provides identical electrical specifications for supply voltage (4.5V ~ 5.5V), output current (4mA), quiescent current (8 µA), and output functions (A<B, A=B, A>B). The 16-SOIC package footprint is mechanically identical. No circuit modification is required.

Q: What is the difference between CD74HCT85M and CD74HCT85MT?

A: Both parts are electrically identical. The primary difference is packaging format: CD74HCT85M is supplied in tube packaging for manual handling, while CD74HCT85MT is supplied in tape and reel format optimized for automated pick-and-place assembly. Select based on your manufacturing process requirements.

Q: Why does the substitute part show faster propagation delay (40ns vs 44ns)?

A: The CD74HCT85M variants demonstrate 40ns propagation delay at 4.5V with 50pF load, compared to 44ns for the original 74HCT85D,652. This represents improved performance and does not affect compatibility. Faster propagation delay provides additional design margin in timing-critical applications.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All listed substitute parts (CD74HCT85M, CD74HCT85M96, CD74HCT85MT) are ROHS3 compliant with MSL 1 (unlimited moisture sensitivity level), matching the original part's environmental and regulatory classification.

Q: What is the significance of the "Discontinued at DiGi Electronics" status for CD74HCT85M96?

A: This designation indicates the part is no longer actively stocked by DiGi Electronics but may remain available through other distributors. For new designs and long-term procurement, CD74HCT85M or CD74HCT85MT are recommended due to their active product status with Texas Instruments.

Q: Can I use these substitutes in designs requiring the -40°C to 125°C temperature range?

A: Yes. The substitute parts support -55°C to 125°C operating range, which encompasses the original -40°C to 125°C specification. The extended lower temperature range provides additional operational margin.