FST3244WMX Equivalent & Substitute Parts

Part Overview

The FST3244WMX is a bus switch IC manufactured by onsemi, configured as a 4 x 1:1 logic switch in a 20-SOIC surface mount package. This component is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production support. Bus switches of this type are used in applications requiring multiplexing or isolation of digital signal paths with minimal propagation delay and low on-resistance characteristics.

Substiute Parts

FST3244WMX

onsemiIn Stock: 982FST3244WMX Datasheet

Current PartRFQ

SN74CBT3244CDW

Texas InstrumentsIn Stock: 2237SN74CBT3244CDW Datasheet

SimilarRFQ

SN74CBT3244DW

Texas InstrumentsIn Stock: 1984SN74CBT3244DW Datasheet

SimilarRFQ

SN74CBT3244DWR

Texas InstrumentsIn Stock: 2725SN74CBT3244DWR Datasheet

SimilarRFQ

SN74CBT3244CDWR

Texas InstrumentsIn Stock: 3009SN74CBT3244CDWR Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the FST3244WMX is determined by strict equivalence across the following parameters:

• Circuit Configuration: All substitutes must maintain 4 x 1:1 topology with 2 independent circuits
• Package / Case: All substitutes must use 20-SOIC (0.295", 7.50mm Width) form factor for PCB compatibility
• Voltage Supply Range: All substitutes must operate within 4V ~ 5.5V or a range that encompasses this specification
• Operating Temperature Range: All substitutes must support -40°C ~ 85°C operation
• Mounting Type: All substitutes must be surface mount compatible

The following Texas Instruments parts meet these strict equivalence criteria and are therefore direct substitutes for the FST3244WMX:

• SN74CBT3244CDW
• SN74CBT3244DW
• SN74CBT3244DWR
• SN74CBT3244CDWR

Parameter Comparison

Engineering Selection Recommendations

Product Status Considerations:

The FST3244WMX is obsolete, necessitating transition to active or last-time-buy alternatives. Among the qualified substitutes:

• SN74CBT3244CDWR is recommended as the primary choice due to its active product status and full voltage range compatibility (4V ~ 5.5V), ensuring long-term availability and design stability.

• SN74CBT3244CDW is an active alternative with identical electrical specifications and full voltage range support, available in tube packaging.

• SN74CBT3244DW and SN74CBT3244DWR are classified as last-time-buy, indicating limited future availability. These parts operate within a narrower voltage range (4.5V ~ 5.5V) and should be selected only when the 4V minimum supply voltage is not required.

Compliance & Certifications:

All Texas Instruments substitutes carry ROHS3 compliance, providing environmental and regulatory advantages over the obsolete onsemi part. All parts maintain identical REACH unaffected status and EAR99 export classification.

Packaging Considerations:

• SN74CBT3244CDW and SN74CBT3244DW are supplied in tube packaging
• SN74CBT3244DWR and SN74CBT3244CDWR are supplied in tape & reel format

Selection between packaging options depends on production volume and assembly line requirements.

Frequently Asked Questions (FAQ)

Q: Can SN74CBT3244DW be used as a direct replacement for FST3244WMX?

A: SN74CBT3244DW is electrically equivalent in circuit configuration, package, and temperature range. However, its voltage supply range is 4.5V ~ 5.5V, which is narrower than the FST3244WMX specification of 4V ~ 5.5V. Use this part only if your application operates at 4.5V or higher.

Q: What is the difference between SN74CBT3244CDW and SN74CBT3244CDWR?

A: Both parts are identical in electrical specifications and voltage range (4V ~ 5.5V). The primary difference is packaging: CDW is supplied in tube format, while CDWR is supplied in tape & reel format. Select based on your assembly process requirements.

Q: Why is SN74CBT3244CDWR recommended over other substitutes?

A: SN74CBT3244CDWR has active product status, ensuring continued availability and support. It also maintains the full voltage range specification (4V ~ 5.5V) matching the original FST3244WMX, providing maximum design flexibility.

Q: Are all substitute parts RoHS compliant?

A: Yes. All Texas Instruments substitutes (SN74CBT3244CDW, SN74CBT3244DW, SN74CBT3244DWR, SN74CBT3244CDWR) are ROHS3 compliant. The original FST3244WMX RoHS status was not specified in the provided data.

Q: Can I use these substitutes interchangeably on the same PCB?

A: Yes, all four substitute parts use the identical 20-SOIC package footprint and are pin-compatible. They can be used interchangeably from a PCB layout perspective. Verify voltage supply range compatibility with your application before selection.

Q: What is the MSL rating for these parts?

A: All parts, including the original FST3244WMX and all substitutes, carry an MSL rating of 1 (Unlimited), indicating no moisture sensitivity restrictions during storage or handling.