CY74FCT646CTSOCT Equivalent & Substitute Parts

Part Overview

The CY74FCT646CTSOCT is a non-inverting transceiver logic integrated circuit manufactured by Texas Instruments, classified within the 74FCT series. This device functions as a 1-element, 8-bit transceiver with 3-state output capability, housed in a 24-SOIC surface mount package. The part is currently listed as obsolete, making identification of functionally equivalent alternatives essential for design continuity and procurement planning. Substitute parts must maintain identical electrical performance characteristics and package specifications to ensure direct replacement capability in existing circuit designs.

Substiute Parts

CY74FCT646CTSOCT

Texas InstrumentsIn Stock: 3901CY74FCT646CTSOCT Datasheet

Current PartRFQ

CY74FCT543TSOCT

Texas InstrumentsIn Stock: 1995CY74FCT543TSOCT Datasheet

Parametric EquivalentRFQ

CY74FCT646ATSOCT

Texas InstrumentsIn Stock: 3045CY74FCT646ATSOCT Datasheet

Parametric EquivalentRFQ

CY74FCT646TSOCT

Texas InstrumentsIn Stock: 1070CY74FCT646TSOCT Datasheet

Parametric EquivalentRFQ

CY74FCT652ATSOCT

Texas InstrumentsIn Stock: 1922CY74FCT652ATSOCT Datasheet

Parametric EquivalentRFQ

CY74FCT652CTSOCT

Texas InstrumentsIn Stock: 3178CY74FCT652CTSOCT Datasheet

Parametric EquivalentRFQ

MC74ACT646DWG

onsemiIn Stock: 972MC74ACT646DWG Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the CY74FCT646CTSOCT are classified based on strict parametric equivalence. All qualified substitutes must satisfy the following criteria:

Critical Matching Parameters:

• Logic type: Transceiver, Non-Inverting
• Number of elements: 1
• Bits per element: 8
• Output type: 3-State
• Current output specifications: 32mA (high) / 64mA (low)
• Supply voltage range: 4.75V – 5.25V
• Operating temperature range: -40°C to +85°C
• Package: 24-SOIC with identical physical dimensions
• Mounting type: Surface Mount

Parametric Equivalent Substitutes maintain all electrical and mechanical specifications identical to the main part. These parts are direct functional replacements with no design modifications required.

Manufacturer Recommended Substitute (MC74ACT646DWG from onsemi) operates within compatible but distinct electrical parameters and represents an alternative technology node within the same functional family.

Parameter Comparison

Engineering Selection Recommendations

Parametric Equivalent Substitutes (Direct Replacements):

The following parts are fully equivalent to CY74FCT646CTSOCT and require no circuit modifications:

• CY74FCT646TSOCT (Active status, 963 units available)
• CY74FCT646ATSOCT (Active status, 2987 units available)
• CY74FCT543TSOCT (Active status, 1900 units available)
• CY74FCT652CTSOCT (Active status, 3116 units available)
• CY74FCT652ATSOCT (Active status, 1814 units available)

All five parts maintain identical electrical specifications, package dimensions, and compliance certifications. Selection among these options should prioritize availability and procurement lead times. Parts with active product status are preferred for long-term supply chain stability.

Manufacturer Recommended Alternative:

MC74ACT646DWG (onsemi) represents a manufacturer-recommended alternative within the 74ACT logic family. This part differs in the following parameters:

• Output current: 24mA (both high and low) versus 32mA/64mA
• Supply voltage range: 4.5V – 5.5V (broader tolerance)
• MSL rating: 3 (168 Hours) versus 1 (Unlimited)
• Product status: Obsolete

This alternative is suitable only when circuit design accommodates the reduced output current specifications and when moisture sensitivity handling procedures align with MSL-3 requirements.

Frequently Asked Questions (FAQ)

Q: Can CY74FCT646CTSOCT be replaced with any of the five parametric equivalent parts without design changes?

A: Yes. CY74FCT646TSOCT, CY74FCT646ATSOCT, CY74FCT543TSOCT, CY74FCT652CTSOCT, and CY74FCT652ATSOCT are parametric equivalents with identical electrical and mechanical specifications. Direct substitution is possible without circuit modifications.

Q: What is the difference between the CY74FCT646 and CY74FCT652 variants?

A: Both variants maintain identical electrical parameters as specified in this reference. Substitution between these base product numbers is supported based on the provided parametric data.

Q: Is MC74ACT646DWG a direct replacement?

A: MC74ACT646DWG is a manufacturer-recommended alternative, not a direct parametric equivalent. The reduced output current (24mA versus 32mA/64mA) and different MSL rating require circuit design verification before implementation.

Q: Why is the original CY74FCT646CTSOCT listed as obsolete?

A: Obsolete status indicates the part is no longer manufactured. The five active parametric equivalents provide continuity for designs requiring this functionality.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All listed substitutes, including the main part, maintain ROHS3 compliance and REACH unaffected status.

Q: What is the significance of MSL-1 versus MSL-3 rating?

A: MSL-1 (Unlimited) allows indefinite storage without moisture baking requirements. MSL-3 (168 Hours) requires moisture baking procedures if storage exceeds 168 hours in high-humidity environments. This affects handling and storage protocols but not electrical functionality.

Q: Can parts be mixed from different manufacturers in the same design?

A: All parametric equivalents are from Texas Instruments. The onsemi alternative (MC74ACT646DWG) operates under different electrical specifications and should not be mixed with FCT-series parts in the same circuit without design verification.