FSV340AF Equivalent & Substitute Parts

Part Overview

The FSV340AF is a Schottky rectifier diode manufactured by onsemi, rated for 40 V DC reverse voltage and 3 A average rectified current in a DO-214AD (SMAF) surface mount package. This component is classified as obsolete product status. Equivalent and substitute parts are necessary to maintain design continuity and ensure component availability for new production runs, repairs, and legacy system support.

Substiute Parts

FSV340AF

onsemiIn Stock: 24522FSV340AF Datasheet

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MBRAF440T3G

onsemiIn Stock: 54007MBRAF440T3G Datasheet

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SS24FSH

Taiwan Semiconductor CorporationIn Stock: 816SS24FSH Datasheet

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VSSAF3L45-M3/6A

Vishay General Semiconductor - Diodes DivisionIn Stock: 2178VSSAF3L45-M3/6A Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the FSV340AF is determined by the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Voltage - DC Reverse (Vr) rating must equal or exceed 40 V
• Current - Average Rectified (Io) rating must equal or exceed 3 A
• Technology must be Schottky
• Speed classification must be Fast Recovery (≤ 500ns, > 200mA)
• Operating temperature range must encompass -55°C to 150°C junction temperature

Mechanical Compatibility Criteria:

• Mounting type must be Surface Mount
• Package footprint must be compatible with DO-214AD or equivalent land pattern

Compliance Criteria:

• RoHS3 compliance required
• MSL rating of 1 (Unlimited) preferred

The substitute parts listed below meet these criteria with variations in current rating, forward voltage, and package form factor that do not compromise functional performance in the FSV340AF application.

Parameter Comparison

Engineering Selection Recommendations

MBRAF440T3G (onsemi)

The MBRAF440T3G is an active product from the same manufacturer as the FSV340AF. It provides 4 A current rating, exceeding the 3 A requirement of the original part. Forward voltage is lower at 485 mV @ 4 A compared to 500 mV @ 3 A. The package is DO-221AC (SMA Flat Leads) rather than DO-214AD, requiring PCB layout modification. All compliance certifications match the original part. This substitute is suitable for applications where the higher current rating and improved forward voltage characteristics provide design margin.

VSSAF3L45-M3/6A (Vishay General Semiconductor)

The VSSAF3L45-M3/6A is an active product from Vishay's TMBS® series with matching 3 A current rating and -55°C to 150°C operating range. The voltage rating is 45 V, providing 5 V additional margin over the 40 V requirement. Forward voltage is 540 mV @ 3 A, slightly higher than the original 500 mV @ 3 A. The package is DO-221AC (SlimSMA), requiring PCB layout modification. All compliance certifications match the original part. This substitute is suitable for applications requiring higher voltage margin and is available in active production status.

SS24FSH (Taiwan Semiconductor Corporation)

The SS24FSH is an active product with automotive qualification (AEC-Q101) and 2 A current rating. The 2 A rating is below the 3 A requirement of the FSV340AF and is not suitable as a direct substitute for applications requiring full 3 A capacity. Forward voltage is 570 mV @ 2 A, higher than the original specification. The package is SOD-128, significantly different from DO-214AD, requiring substantial PCB redesign. This part is suitable only for applications with reduced current requirements or as a secondary option where current derating is acceptable.

Frequently Asked Questions (FAQ)

Q: Can the MBRAF440T3G directly replace the FSV340AF without PCB modification?

A: No. While both are surface mount Schottky diodes with compatible electrical specifications, the MBRAF440T3G uses a DO-221AC (SMA Flat Leads) package versus the FSV340AF's DO-214AD (SMAF) package. These packages have different footprints and require PCB layout changes.

Q: Is the VSSAF3L45-M3/6A suitable for 40 V applications?

A: Yes. The VSSAF3L45-M3/6A is rated for 45 V DC reverse voltage, which exceeds the 40 V requirement. It is suitable for applications designed for 40 V operation.

Q: Why is the SS24FSH listed as a substitute if it has only 2 A rating?

A: The SS24FSH meets the core Schottky diode specifications and compliance requirements but with reduced current capacity. It is listed as a substitute for applications where current requirements are 2 A or less, or where design margin allows for current derating. It is not suitable for applications requiring the full 3 A specification of the FSV340AF.

Q: What is the impact of higher reverse leakage current in substitute parts?

A: The MBRAF440T3G exhibits 300 µA reverse leakage at 40 V compared to 100 µA for the FSV340AF. The VSSAF3L45-M3/6A exhibits 450 µA at 45 V. Higher reverse leakage increases power dissipation in reverse bias conditions and may affect circuit performance in applications sensitive to leakage current. Circuit analysis is required to determine acceptability.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All listed substitute parts are RoHS3 compliant with MSL rating of 1 (Unlimited), matching the compliance profile of the FSV340AF.

Q: What is the difference between DO-214AD and DO-221AC packages?

A: DO-214AD (SMAF) and DO-221AC (SMA Flat Leads) are both surface mount packages for Schottky diodes but have different physical dimensions and land patterns. DO-221AC is typically larger. PCB footprint compatibility must be verified before substitution.

Q: Can the VSSAF3L45-M3/6A be used in applications with -55°C minimum operating temperature?

A: The VSSAF3L45-M3/6A is rated for -40°C to 150°C junction temperature, which does not extend to -55°C. The FSV340AF and MBRAF440T3G both support -55°C to 150°C. For applications requiring -55°C operation, the VSSAF3L45-M3/6A is not suitable.