FST3253MX Equivalent & Substitute Parts

Part Overview

The FST3253MX is a 2 x 4:1 Multiplexer/Demultiplexer logic integrated circuit manufactured by onsemi in a 16-SOIC surface mount package. This part is classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing production support. The FST3253MX operates with single supply voltage between 4V and 5.5V across an operating temperature range of -40°C to 85°C, serving applications requiring high-speed signal routing and multiplexing functions.

Substiute Parts

FST3253MX

onsemiIn Stock: 1266FST3253MX Datasheet

Current PartRFQ

SN74CBT3253CDR

Texas InstrumentsIn Stock: 3461SN74CBT3253CDR Datasheet

DirectRFQ

SN74CBT3253D

Texas InstrumentsIn Stock: 2649SN74CBT3253D Datasheet

DirectRFQ

SN74CBT3253DR

Texas InstrumentsIn Stock: 8661SN74CBT3253DR Datasheet

DirectRFQ

CBT3253AD,118

Nexperia USA Inc.In Stock: 830CBT3253AD,118 Datasheet

SimilarRFQ

CBT3253D,118

Nexperia USA Inc.In Stock: 1154CBT3253D,118 Datasheet

SimilarRFQ

QS3253S1G8

IDT, Integrated Device Technology IncIn Stock: 2302QS3253S1G8 Datasheet

SimilarRFQ

SN74CBT3253CD

Texas InstrumentsIn Stock: 1423SN74CBT3253CD Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the FST3253MX are qualified based on the following electrical and mechanical parameters:

Critical Matching Parameters:

• Circuit configuration: 2 x 4:1 multiplexer/demultiplexer topology
• Package type: 16-SOIC surface mount package with 0.154" (3.90mm) width
• Voltage supply source: Single supply operation
• Operating temperature range: -40°C to 85°C minimum
• Mounting type: Surface mount

Substitution Categories:

Direct Substitutes maintain identical electrical specifications and packaging. These parts are pin-compatible and functionally equivalent with no design modifications required.

Similar Substitutes share the same circuit configuration, package footprint, and operating parameters but may originate from different manufacturers or have minor specification variations within acceptable ranges. These require verification of voltage supply tolerance and operating temperature compliance.

Parameter Comparison

Engineering Selection Recommendations

Preferred Substitutes for Active Production:

SN74CBT3253CD and SN74CBT3253CDR from Texas Instruments are recommended as primary substitutes. Both parts maintain active product status, provide ROHS3 compliance, and operate within the required voltage and temperature specifications. The voltage supply range of 4.5V to 5.5V is compatible with the FST3253MX operating envelope. SN74CBT3253CDR in Tape & Reel packaging is suitable for automated assembly processes, while SN74CBT3253CD in Tube packaging accommodates manual assembly or lower-volume applications.

Alternative Substitutes:

CBT3253AD,118 from Nexperia USA Inc. provides an active product status alternative with ROHS3 compliance and identical electrical specifications. This part supports continued long-term availability.

QS3253S1G8 from IDT maintains active status and meets the circuit configuration and package requirements. The voltage supply range of 4.75V to 5.25V is narrower than the FST3253MX but remains compatible with standard 5V logic supply systems.

End-of-Life Alternatives:

SN74CBT3253D and SN74CBT3253DR from Texas Instruments carry Last Time Buy status. These parts remain functionally equivalent but have limited future availability. Selection should account for long-term supply chain requirements.

Frequently Asked Questions (FAQ)

Q: Can SN74CBT3253CDR directly replace FST3253MX without PCB modifications?

A: Yes. Both parts share identical 16-SOIC package dimensions (0.154" width, 3.90mm), pin count, and circuit configuration. No PCB layout changes are required for direct substitution.

Q: What is the voltage supply compatibility between FST3253MX and substitute parts?

A: The FST3253MX operates at 4V to 5.5V. Most substitute parts (SN74CBT3253 series, CBT3253AD,118) operate at 4.5V to 5.5V, which is compatible with standard 5V supply systems. QS3253S1G8 operates at 4.75V to 5.25V, also suitable for 5V applications. Verify your specific supply voltage falls within the substitute part's rated range.

Q: Are all substitute parts RoHS compliant?

A: Texas Instruments SN74CBT3253 series and Nexperia CBT3253 series parts are ROHS3 compliant. QS3253S1G8 from IDT does not specify RoHS status in the provided data. Confirm RoHS compliance requirements for your application before selection.

Q: What packaging options are available for substitutes?

A: SN74CBT3253CDR is supplied in Tape & Reel (TR) packaging for automated pick-and-place assembly. SN74CBT3253CD is supplied in Tube packaging for manual handling. CBT3253AD,118 and CBT3253D,118 are supplied in Tape & Reel. QS3253S1G8 is supplied in Bulk packaging. Select packaging based on your assembly process requirements.

Q: Which substitute offers the longest product lifecycle?

A: SN74CBT3253CD, CBT3253AD,118, CBT3253D,118, and QS3253S1G8 all maintain active product status, indicating ongoing manufacturer support and availability. These are preferred for new designs requiring long-term supply assurance.

Q: Is the FST3253MX obsolete status a concern for substitution?

A: Yes. The obsolete status indicates onsemi has discontinued this part. Substitution is necessary for continued production support. Active-status alternatives from Texas Instruments, Nexperia, and IDT provide equivalent functionality with assured future availability.