CY74FCT257ATDR Equivalent & Substitute Parts

Part Overview

The CY74FCT257ATDR is a 4 x 2:1 multiplexer logic IC manufactured by Texas Instruments in a 16-SOIC surface mount package. This component is classified as obsolete, making identification of compatible substitute parts essential for ongoing design support and production continuity. The part operates on single supply voltage (4.75V ~ 5.25V) and is suitable for applications requiring multiplexing functionality in standard TTL logic circuits.

Substiute Parts

CY74FCT257ATDR

Texas InstrumentsIn Stock: 958CY74FCT257ATDR Datasheet

Current PartRFQ

CY74FCT157ATDR

Texas InstrumentsIn Stock: 1957CY74FCT157ATDR Datasheet

Parametric EquivalentRFQ

CY74FCT157CTDR

Texas InstrumentsIn Stock: 849CY74FCT157CTDR Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the CY74FCT257ATDR is determined by strict equivalence across the following critical parameters:

• Circuit configuration: 4 x 2:1 multiplexer topology
• Output current specifications: 32mA high, 64mA low
• Supply voltage range: 4.75V ~ 5.25V
• Operating temperature range: -40°C ~ 85°C
• Package type: 16-SOIC surface mount
• Electrical characteristics: Single supply operation

The identified substitute parts (CY74FCT157ATDR and CY74FCT157CTDR) maintain identical electrical performance and physical packaging, enabling direct functional replacement in circuit applications. Substitution is based solely on matching these defined parameters without deviation.

Parameter Comparison

Engineering Selection Recommendations

For applications currently using the CY74FCT257ATDR, the CY74FCT157ATDR is the primary recommended substitute. This part maintains active product status with Texas Instruments, ensuring ongoing availability and supply chain reliability. Both parts are ROHS3 compliant and carry identical electrical and mechanical specifications.

The CY74FCT157CTDR represents a secondary option with equivalent electrical performance and packaging. However, this part is discontinued at DiGi Electronics, which may impact long-term procurement availability. Selection between these substitutes should be based on supply chain accessibility and inventory requirements for your specific application timeline.

All three parts satisfy identical functional requirements and are suitable for direct replacement without circuit modification.

Frequently Asked Questions (FAQ)

Q: Can CY74FCT157ATDR directly replace CY74FCT257ATDR in existing designs?

A: Yes. Both parts share identical circuit configuration (4 x 2:1 multiplexer), output current ratings (32mA high, 64mA low), supply voltage range (4.75V ~ 5.25V), operating temperature range (-40°C ~ 85°C), and 16-SOIC package specifications. Direct substitution is electrically and mechanically compatible.

Q: What is the difference between CY74FCT157ATDR and CY74FCT157CTDR?

A: Both parts are parametrically equivalent with identical electrical characteristics and packaging. The primary difference is product status: CY74FCT157ATDR maintains active status, while CY74FCT157CTDR is discontinued at DiGi Electronics. For new designs and ongoing production, CY74FCT157ATDR is the preferred choice.

Q: Are there any package or pinout differences between these parts?

A: No. All three parts use the 16-SOIC (0.154", 3.90mm Width) surface mount package with identical pinout and mechanical dimensions. PCB layout and assembly processes require no modification.

Q: Do these parts meet current compliance requirements?

A: Yes. All substitute parts are ROHS3 compliant with Moisture Sensitivity Level 1 (Unlimited), matching the compliance profile of the original CY74FCT257ATDR.

Q: Which substitute should be selected for new production?

A: CY74FCT157ATDR is recommended for new production due to active product status and confirmed supply availability. This ensures design continuity and reduces long-term supply chain risk.