74FST3257DTR2G Equivalent & Substitute Parts

Part Overview

The 74FST3257DTR2G is a 4 x 2:1 Multiplexer/Demultiplexer logic IC manufactured by onsemi in 16-TSSOP surface mount packaging. This component is classified as Last Time Buy, indicating limited availability from the original manufacturer. Finding equivalent and substitute parts is necessary to ensure design continuity and supply chain reliability for new production runs and long-term support.

Substiute Parts

74FST3257DTR2G

onsemiIn Stock: 330374FST3257DTR2G Datasheet

Current PartRFQ

FST3257MTCX

onsemiIn Stock: 55297FST3257MTCX Datasheet

DirectRFQ

CBT3257APW,118

Nexperia USA Inc.In Stock: 3196CBT3257APW,118 Datasheet

DirectRFQ

SN74CBT3257CPW

Texas InstrumentsIn Stock: 2206SN74CBT3257CPW Datasheet

DirectRFQ

SN74CBT3257CPWR

Texas InstrumentsIn Stock: 47791SN74CBT3257CPWR Datasheet

DirectRFQ

SN74CBT3257PW

Texas InstrumentsIn Stock: 2324SN74CBT3257PW Datasheet

DirectRFQ

SN74CBT3257PWR

Texas InstrumentsIn Stock: 2476SN74CBT3257PWR Datasheet

DirectRFQ

PI5C3257LE

Diodes IncorporatedIn Stock: 1443PI5C3257LE Datasheet

SimilarRFQ

PI5C3257LEX

Diodes IncorporatedIn Stock: 15451PI5C3257LEX Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 74FST3257DTR2G is determined by the following critical parameters:

Functional Equivalence: All substitute parts must implement a 4 x 2:1 Multiplexer/Demultiplexer circuit with identical pin configuration and functional behavior.

Package Compatibility: All parts must use 16-TSSOP surface mount packaging with identical physical dimensions (0.173", 4.40mm Width) to ensure PCB layout compatibility without redesign.

Voltage Supply Range: Substitute parts must operate within or encompass the 4V ~ 5.5V supply range. Parts with narrower ranges (such as 4.5V ~ 5.5V) are acceptable if the design operates within their specified limits.

Temperature Range: All parts must support the -40°C ~ 85°C operating temperature range.

Compliance Standards: All substitute parts must maintain ROHS3 compliance and MSL 1 rating to meet regulatory and manufacturing requirements.

Substitute parts are categorized as Direct Substitutes (identical electrical and mechanical specifications) or Similar Substitutes (minor parameter variations within acceptable engineering tolerances).

Parameter Comparison

Engineering Selection Recommendations

Direct Substitutes (Recommended for New Designs):

The Texas Instruments SN74CBT3257CPWR and SN74CBT3257CPW are the preferred direct substitutes. Both parts carry Active product status, ensuring long-term availability and manufacturer support. The SN74CBT3257CPWR offers the highest inventory (47,740 units) and is available in Cut Tape & Digi-Reel® packaging, suitable for high-volume production. The SN74CBT3257CPW provides equivalent functionality in Tube packaging for lower-volume applications.

Alternative Direct Substitutes:

The Nexperia CBT3257APW,118 is an Active product with adequate inventory (3,127 units) and Tape & Reel packaging. This part provides a secondary sourcing option from an established manufacturer.

Compatibility Considerations:

The FST3257MTCX from onsemi has higher inventory availability (55,200 units) but carries Obsolete status. This part features an extended lower voltage limit (3V minimum) compared to the main part (4V minimum), making it suitable only for designs operating at 4V or above. The PI5C3257LE and PI5C3257LEX from Diodes Incorporated have narrower voltage ranges (4.75V ~ 5.25V) and Last Time Buy status, limiting their suitability for new long-term designs.

Supply Chain Strategy:

For immediate production needs, SN74CBT3257CPWR provides the largest available inventory with Active status. For designs requiring Tape & Reel packaging with long-term support, CBT3257APW,118 from Nexperia offers a reliable alternative. Avoid parts with Last Time Buy or Obsolete status for new product designs unless existing inventory commitments require their use.

Frequently Asked Questions (FAQ)

Q: Can I use SN74CBT3257CPWR as a direct replacement for 74FST3257DTR2G without PCB modifications?

A: Yes. Both parts use identical 16-TSSOP packaging with the same physical dimensions and pin configuration. No PCB layout changes are required. The voltage supply range difference (4.5V ~ 5.5V vs. 4V ~ 5.5V) is not a concern if your design operates at 4.5V or above.

Q: What is the difference between the various Texas Instruments CBT3257 part numbers?

A: The primary differences are packaging type and product status. SN74CBT3257CPWR uses Cut Tape & Digi-Reel® packaging and is Active (recommended). SN74CBT3257CPW uses Tube packaging and is Active. SN74CBT3257PW and SN74CBT3257PWR are Last Time Buy variants. All share identical electrical specifications.

Q: Why does FST3257MTCX have lower voltage specification (3V minimum) than the main part?

A: FST3257MTCX is an onsemi variant with extended lower voltage capability. It is functionally compatible with 74FST3257DTR2G but carries Obsolete status. Use this part only if your design operates within its 3V ~ 5.5V range and existing inventory is available.

Q: Are PI5C3257LE and PI5C3257LEX suitable for new production designs?

A: Both Diodes Incorporated parts carry Last Time Buy status with limited inventory. They feature a narrower voltage range (4.75V ~ 5.25V) compared to the main part. These parts are suitable only for designs already committed to their use or for applications where the narrower voltage range is acceptable.

Q: What packaging options are available for high-volume production?

A: SN74CBT3257CPWR (47,740 units) and PI5C3257LEX (15,417 units) are available in Tape & Reel packaging suitable for automated assembly. SN74CBT3257CPWR is the recommended choice due to its Active status and highest inventory level.

Q: Do all substitute parts meet the same compliance standards?

A: Yes. All listed substitute parts are ROHS3 compliant with MSL 1 (Unlimited) moisture sensitivity rating, matching the main part's compliance profile.