FSUSB31L8X USB Switch IC Equivalent & Substitute Parts

Part Overview

The FSUSB31L8X is a USB Switch IC manufactured by onsemi, designed for single-channel USB 2.0 switching applications. This component features a DPST (Double Pole Single Throw) switch circuit with 1 channel and operates across a 3V to 4.3V supply voltage range. The part is classified as obsolete, making identification of functionally equivalent alternatives necessary for ongoing design support and procurement planning.

Substiute Parts

FSUSB31L8X

onsemiIn Stock: 4225FSUSB31L8X Datasheet

Current PartRFQ

TS3USB31ERSER

Texas InstrumentsIn Stock: 22932TS3USB31ERSER Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the FSUSB31L8X is determined by the following critical parameters:

• Switch Circuit Configuration: DPST topology with single-channel operation
• On-State Resistance: Maximum 10 Ohm specification
• Supply Voltage Compatibility: Operating range must encompass or exceed 3V to 4.3V
• Bandwidth Performance: Minimum 720 MHz -3dB bandwidth for USB 2.0 signal integrity
• Package Compatibility: 8-UFQFN surface mount package
• Operating Temperature Range: -40°C to 85°C minimum coverage
• Regulatory Compliance: ROHS3 compliance and MSL 1 rating

The TS3USB31ERSER from Texas Instruments meets all substitution criteria. Both parts share identical switch circuit topology, channel count, on-state resistance specification, package form factor, temperature range, and regulatory compliance status. The TS3USB31ERSER provides enhanced supply voltage flexibility (2.25V to 4.3V) and superior bandwidth performance (1.1 GHz), making it functionally compatible for applications designed around the FSUSB31L8X.

Parameter Comparison

Engineering Selection Recommendations

The TS3USB31ERSER is the qualified substitute for the obsolete FSUSB31L8X. Selection is based on the following engineering criteria:

• Functional Equivalence: Both parts implement identical DPST switch topology with single-channel configuration and matching on-state resistance specifications.
• Electrical Compatibility: The TS3USB31ERSER operates within the FSUSB31L8X supply voltage range (2.25V to 4.3V encompasses 3V to 4.3V) and exceeds bandwidth requirements (1.1 GHz versus 720 MHz).
• Package Compatibility: Both components use 8-UFQFN surface mount packaging, enabling direct PCB layout compatibility without redesign.
• Regulatory Alignment: Both parts maintain ROHS3 compliance and MSL 1 rating, satisfying environmental and reliability requirements.
• Product Status: The TS3USB31ERSER maintains active product status with established supply chain availability, addressing the obsolescence of the FSUSB31L8X.

Frequently Asked Questions (FAQ)

Q: Can the TS3USB31ERSER directly replace the FSUSB31L8X without PCB modifications?

A: Yes. Both parts share identical 8-UFQFN package geometry and pinout configuration, enabling direct substitution without PCB layout changes.

Q: What are the key electrical differences between these parts?

A: The TS3USB31ERSER provides extended supply voltage range (2.25V minimum versus 3V minimum) and higher bandwidth performance (1.1 GHz versus 720 MHz). Both maintain identical on-state resistance (10 Ohm maximum) and operating temperature range (-40°C to 85°C).

Q: Are there any compliance or certification differences?

A: No. Both parts are ROHS3 compliant with MSL 1 rating. Regulatory classifications (ECCN: EAR99, HTSUS: 8542.39.0001) are identical.

Q: Why is the FSUSB31L8X classified as obsolete?

A: Product status reflects onsemi's discontinuation of this part number. The TS3USB31ERSER from Texas Instruments provides equivalent functionality with active manufacturing support.

Q: Are there any application limitations when substituting to the TS3USB31ERSER?

A: No limitations exist for USB 2.0 switching applications. The TS3USB31ERSER's enhanced bandwidth and extended voltage range provide equivalent or superior performance across all specified operating conditions.

Q: What is the moisture sensitivity level, and does it affect handling?

A: Both parts carry MSL 1 rating, indicating unlimited shelf life without moisture absorption concerns. Standard surface mount handling procedures apply.