74ACTQ646SC Equivalent & Substitute Parts

Part Overview

The 74ACTQ646SC is a non-inverting transceiver logic IC manufactured by onsemi, featuring 1 element with 8 bits per element and 3-state output capability. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement continuity. The 24-SOP surface mount package and 4.5V to 5.5V supply voltage range define its operational envelope across industrial and commercial applications.

Substiute Parts

74ACTQ646SC

onsemiIn Stock: 225174ACTQ646SC Datasheet

Current PartRFQ

MC74ACT646DWR2G

onsemiIn Stock: 972MC74ACT646DWR2G Datasheet

SimilarRFQ

CD74ACT646M

Harris CorporationIn Stock: 1029CD74ACT646M Datasheet

SimilarRFQ

CD74ACT646M96

Texas InstrumentsIn Stock: 1001CD74ACT646M96 Datasheet

SimilarRFQ

74ACT11245DW

Texas InstrumentsIn Stock: 75274ACT11245DW Datasheet

Parametric EquivalentRFQ

MC74ACT646DWG

onsemiIn Stock: 972MC74ACT646DWG Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 74ACTQ646SC is determined by the following critical parameters:

• Logic Type: Transceiver, Non-Inverting
• Number of Elements: 1
• Number of Bits per Element: 8
• Output Type: 3-State
• Current - Output High, Low: 24mA, 24mA
• Voltage - Supply: 4.5V ~ 5.5V
• Package / Case: 24-SOIC (0.295", 7.50mm Width)

Substitute parts are grouped into two categories:

Direct Substitutes (Identical Base Product Number 74ACT646): Parts sharing the 74ACT646 base product number with matching electrical specifications and package footprint. These include MC74ACT646DWR2G, CD74ACT646M, and CD74ACT646M96.

Parametric Equivalents (Functional Compatibility): Parts with different base product numbers (74ACT11245 series) that meet all critical electrical and mechanical parameters, enabling functional replacement in circuit designs.

Parameter Comparison

Engineering Selection Recommendations

For Active Product Status Requirement: CD74ACT646M96 is the only substitute with Active product status, making it the preferred choice for new designs requiring long-term availability and manufacturer support.

For RoHS3 Compliance: MC74ACT646DWR2G, CD74ACT646M96, 74ACT11245DW, and MC74ACT646DWG all meet ROHS3 compliance requirements. CD74ACT646M is RoHS non-compliant and should be avoided in applications requiring environmental compliance.

For Extended Temperature Range: CD74ACT646M and CD74ACT646M96 support -55°C to 125°C operating temperature, compared to the original part's -40°C to 85°C range. These options provide thermal margin for demanding industrial applications.

For Moisture Sensitivity: 74ACTQ646SC, CD74ACT646M96, and 74ACT11245DW maintain MSL 1 (Unlimited) rating, eliminating moisture-related handling constraints. MC74ACT646DWR2G and MC74ACT646DWG carry MSL 3 (168 Hours) ratings, requiring controlled storage and handling procedures.

For Packaging Format: All substitutes are available in 24-SOIC surface mount package with identical 0.295" (7.50mm) width, ensuring direct PCB footprint compatibility without layout modifications.

Frequently Asked Questions (FAQ)

Q: Can MC74ACT646DWR2G directly replace 74ACTQ646SC in existing designs? A: Yes. MC74ACT646DWR2G shares the 74ACT646 base product number and matches all critical electrical parameters (24mA output current, 4.5V–5.5V supply, 3-state output, 8-bit configuration) and 24-SOIC package footprint. The MSL 3 rating requires controlled storage conditions during manufacturing.

Q: What is the difference between direct substitutes and parametric equivalents? A: Direct substitutes (MC74ACT646DWR2G, CD74ACT646M, CD74ACT646M96) share the 74ACT646 base product number. Parametric equivalents (74ACT11245DW, MC74ACT646DWG) use different base product numbers but deliver identical functional performance through matching electrical specifications and package compatibility.

Q: Is CD74ACT646M96 suitable for new production designs? A: Yes. CD74ACT646M96 is the only substitute with Active product status, ROHS3 compliance, MSL 1 rating, and extended temperature range (-55°C to 125°C). It is the recommended choice for designs requiring long-term component availability.

Q: Why is CD74ACT646M marked as RoHS non-compliant? A: CD74ACT646M does not meet ROHS3 environmental compliance standards. It should be selected only for legacy applications or non-regulated markets where RoHS compliance is not required.

Q: Are all substitutes pin-compatible with 74ACTQ646SC? A: All listed substitutes use the 24-SOIC package with identical 0.295" (7.50mm) width and pin configuration, ensuring direct pin-for-pin compatibility without circuit modifications.

Q: What handling precautions apply to substitutes with MSL 3 rating? A: Parts with MSL 3 (168 Hours) rating—MC74ACT646DWR2G and MC74ACT646DWG—must be stored in controlled humidity environments and used within 168 hours of package opening. Baking procedures may be required if storage limits are exceeded.

Q: Can 74ACT11245DW be used as a long-term replacement? A: 74ACT11245DW carries Last Time Buy status, indicating limited future availability. While functionally equivalent, CD74ACT646M96 (Active status) is preferred for designs requiring extended production runs.