74FCT157ATQG Equivalent & Substitute Parts

Part Overview

The 74FCT157ATQG is a 4 x 2:1 multiplexer logic integrated circuit manufactured by IDT (Integrated Device Technology Inc) in a 16-QSOP surface mount package. This component is classified as obsolete, making identification of functionally equivalent alternatives necessary for ongoing system support and new design implementations. The part operates on single supply voltage and is suitable for applications requiring multiplexing of multiple data channels.

Substiute Parts

74FCT157ATQG

IDT, Integrated Device Technology IncIn Stock: 567774FCT157ATQG Datasheet

Current PartRFQ

CY74FCT157CTQCT

Texas InstrumentsIn Stock: 1264CY74FCT157CTQCT Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 74FCT157ATQG is determined by the following critical parameters:

Functional Equivalence Criteria:

• Circuit configuration: 4 x 2:1 multiplexer topology
• Independent circuits: 1
• Voltage supply source: Single supply
• Supply voltage range: 4.75V ~ 5.25V
• Operating temperature range: -40°C ~ 85°C
• Package type: 16-SSOP surface mount

Acceptable Variations:

• Output current specifications (High/Low) may differ while maintaining functional compatibility
• Packaging format (Tube vs. Cut Tape) does not affect electrical compatibility
• Manufacturer origin does not affect substitution eligibility
• Product status transition from obsolete to active is acceptable for replacement applications

The CY74FCT157CTQCT from Texas Instruments meets all functional equivalence criteria and serves as a direct substitute for the 74FCT157ATQG.

Parameter Comparison

Engineering Selection Recommendations

The CY74FCT157CTQCT is a qualified substitute for the 74FCT157ATQG based on the following factors:

Functional Compatibility: Both parts implement identical 4 x 2:1 multiplexer logic with matching voltage supply specifications and operating temperature ranges. Pin configuration and package footprint are identical, enabling direct board-level replacement.

Compliance Status: The substitute part maintains ROHS3 compliance equivalent to the original component. The transition from obsolete to active product status in the substitute part ensures long-term availability and supply chain continuity.

Output Current Differential: The CY74FCT157CTQCT provides higher output current specifications (32mA high, 64mA low) compared to the original part (15mA high, 48mA low). This represents an enhancement in drive capability and does not create compatibility issues in applications designed for the original part's specifications.

Supply Chain Consideration: Active product status of the substitute part provides superior availability compared to the obsolete original component.

Frequently Asked Questions (FAQ)

Q: Can the CY74FCT157CTQCT directly replace the 74FCT157ATQG on existing PCBs?

A: Yes. Both parts share identical 16-SSOP package dimensions, pin configuration, and electrical interface specifications. Direct board-level substitution is supported without design modifications.

Q: What is the significance of the higher output current in the substitute part?

A: The CY74FCT157CTQCT provides increased output current capability (32mA/64mA vs. 15mA/48mA). This enhancement does not create compatibility issues. Circuits designed for the original part's current specifications will function correctly with the substitute part.

Q: Are there differences in supply voltage requirements?

A: No. Both parts operate on identical single supply voltage specifications of 4.75V ~ 5.25V. No power supply modifications are required for substitution.

Q: Does the packaging format (Tube vs. Cut Tape) affect substitution?

A: No. Packaging format relates only to component delivery and handling. The electrical and mechanical specifications remain identical regardless of packaging format.

Q: Why is the original part listed as obsolete?

A: Product obsolescence indicates that the manufacturer has discontinued production. The CY74FCT157CTQCT from Texas Instruments provides functional equivalence with active product status, ensuring continued availability for replacement and new applications.

Q: Are both parts RoHS compliant?

A: Yes. Both the 74FCT157ATQG and CY74FCT157CTQCT maintain ROHS3 compliance, meeting environmental and regulatory requirements.