VS3V3BA1FST40NB Equivalent & Substitute Parts

Part Overview

The VS3V3BA1FST40NB is a Transient Voltage Suppressor (TVS) diode manufactured by Rohm Semiconductor, designed for general-purpose overvoltage protection applications. This component features a 3.3V reverse standoff voltage with an 8V maximum clamping voltage and 3.3A peak pulse current rating in a compact 0402 surface mount package.

The product is currently classified as obsolete. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain reliability, and support ongoing production or maintenance requirements for systems utilizing this component.

Substiute Parts

VS3V3BA1FST40NB

Rohm SemiconductorIn Stock: 1134VS3V3BA1FST40NB Datasheet

Current PartRFQ

UCLAMP3331ZATFT

Semtech CorporationIn Stock: 80143UCLAMP3331ZATFT Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the VS3V3BA1FST40NB is determined by the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Voltage - Reverse Standoff (Typ): 3.3V (Max)
• Voltage - Breakdown (Min): 3.9V to 4V range
• Voltage - Clamping (Max) @ Ipp: 8V to 10V range
• Current - Peak Pulse (8/20µs): Minimum 3.3A
• Bidirectional Channels: 1
• Type: Zener TVS Diode

Mechanical Compatibility Criteria:

• Mounting Type: Surface Mount
• Package compatibility: 0402 or equivalent compact surface mount packages
• Moisture Sensitivity Level: 1 (Unlimited)

Compliance Criteria:

• RoHS3 Compliance
• EAR99 ECCN classification

The UCLAMP3331ZATFT from Semtech Corporation meets these substitution criteria with compatible electrical parameters and active product status, making it a suitable alternative for the obsolete VS3V3BA1FST40NB.

Parameter Comparison

Engineering Selection Recommendations

The UCLAMP3331ZATFT is classified as an active product with current manufacturing support, providing supply chain continuity for applications previously using the obsolete VS3V3BA1FST40NB. Both components maintain ROHS3 compliance and EAR99 ECCN classification, ensuring regulatory consistency.

The substitute part demonstrates enhanced electrical performance with higher peak pulse current (5A versus 3.3A) and greater peak pulse power (30W versus 26.5W), providing additional margin in overvoltage protection applications. The clamping voltage differential (10V versus 8V) remains within acceptable tolerance for general-purpose TVS applications operating at 3.3V logic levels.

The package transition from 0402 to 0603 metric represents a minor footprint increase. PCB layout modifications may be required to accommodate the larger package dimensions. The operating temperature range of the substitute part (-40°C ~ 125°C) is narrower than the original component (-55°C ~ 150°C), which may impact suitability for extended temperature applications.

Frequently Asked Questions (FAQ)

Q: Can the UCLAMP3331ZATFT directly replace the VS3V3BA1FST40NB without circuit modifications?

A: Electrical substitution is feasible based on matching reverse standoff voltage (3.3V), bidirectional channel configuration (1), and zener type. However, PCB layout modifications are necessary due to package size change from 0402 to 0603 metric. Verify that the larger footprint accommodates existing PCB routing and component placement constraints.

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

A: The substitute part provides higher peak pulse current (5A versus 3.3A) and clamping voltage (10V versus 8V). These differences represent improved performance margins rather than incompatibility. The breakdown voltage minimum is slightly lower (3.9V versus 4V), remaining within acceptable tolerance for 3.3V protection applications.

Q: Are there temperature range considerations for substitution?

A: The original component operates across -55°C ~ 150°C, while the substitute operates across -40°C ~ 125°C. Applications requiring operation below -40°C or above 125°C junction temperature require alternative component selection.

Q: Do both components meet the same compliance standards?

A: Yes. Both the VS3V3BA1FST40NB and UCLAMP3331ZATFT are ROHS3 compliant with EAR99 ECCN classification and MSL 1 (Unlimited) moisture sensitivity rating, ensuring regulatory and handling consistency.

Q: What is the impact of the package change from 0402 to 0603?

A: The 0603 package is larger than 0402, requiring PCB layout redesign for component placement and trace routing. The larger package may provide improved thermal dissipation characteristics. Verify mechanical compatibility with existing assembly equipment and design constraints before implementation.