FDD5N50UTF_WS N-Channel MOSFET Equivalent & Substitute Parts

Part Overview

The FDD5N50UTF_WS is an N-Channel MOSFET manufactured by onsemi, rated for 500 V drain-to-source voltage with 3 A continuous drain current. This device is housed in a TO-252-3 DPAK surface mount package and is designed for applications requiring high-voltage switching and power dissipation up to 40 W. The part is classified as obsolete, making identification of equivalent and substitute components necessary for ongoing design support, production continuity, and system maintenance.

Substiute Parts

FDD5N50UTF_WS

onsemiIn Stock: 901FDD5N50UTF_WS Datasheet

Current PartRFQ

TK4P50D(T6RSS-Q)

Toshiba Semiconductor and StorageIn Stock: 902TK4P50D(T6RSS-Q) Datasheet

SimilarRFQ

TK4P55D(T6RSS-Q)

Toshiba Semiconductor and StorageIn Stock: 5492TK4P55D(T6RSS-Q) Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the FDD5N50UTF_WS is determined by the following critical electrical and mechanical parameters:

Mandatory Matching Criteria:

• FET Type: N-Channel
• Technology: MOSFET (Metal Oxide)
• Drain to Source Voltage (Vdss): 500 V minimum
• Mounting Type: Surface Mount
• Package / Case: TO-252-3, DPAK (2 Leads + Tab), SC-63

Performance Compatibility Criteria:

• Continuous Drain Current (Id): Equal to or greater than 3 A
• On-State Resistance (Rds On): Equal to or lower than 2 Ω (at rated conditions)
• Power Dissipation: Equal to or greater than 40 W
• Operating Temperature Range: Must encompass −55 to 150 °C

Substitute parts identified below meet or exceed these parameters, ensuring functional and thermal compatibility within the original application envelope.

Parameter Comparison

Engineering Selection Recommendations

TK4P50D(T6RSS-Q) — Primary Substitute

The TK4P50D(T6RSS-Q) from Toshiba Semiconductor and Storage is an active product that directly matches the FDD5N50UTF_WS in voltage rating (500 V Vdss) and package configuration (TO-252-3 DPAK). This device provides superior performance with 4 A continuous drain current versus 3 A, and doubled power dissipation capability (80 W versus 40 W). On-state resistance remains equivalent at 2 Ω. The part is RoHS Compliant and carries active product status, ensuring long-term availability and supply chain stability. This substitute is suitable for direct replacement in applications where the original FDD5N50UTF_WS was specified.

TK4P55D(T6RSS-Q) — Secondary Substitute

The TK4P55D(T6RSS-Q) from Toshiba Semiconductor and Storage is an active product offering enhanced voltage rating (550 V Vdss) compared to the original 500 V specification. This device provides 4 A continuous drain current and improved on-state resistance (1.88 Ω versus 2 Ω), with 80 W power dissipation capability. The higher voltage rating provides additional design margin for applications subject to voltage transients or overvoltage conditions. Package configuration and thermal characteristics remain compatible. This substitute is suitable for applications where increased voltage headroom is beneficial or required.

Both substitute parts are manufactured in active product lines with RoHS compliance, ensuring regulatory alignment and supply continuity.

Frequently Asked Questions (FAQ)

Q: Can the TK4P50D(T6RSS-Q) be used as a direct replacement for the FDD5N50UTF_WS?

A: Yes. Both devices share identical voltage rating (500 V Vdss), identical on-state resistance specification (2 Ω @ 10 V), identical package configuration (TO-252-3 DPAK), and identical gate voltage rating (±30 V). The TK4P50D provides higher continuous drain current (4 A versus 3 A) and greater power dissipation capability (80 W versus 40 W), making it functionally compatible and superior in thermal performance.

Q: What is the difference between the TK4P50D and TK4P55D substitutes?

A: The primary difference is drain-to-source voltage rating: TK4P50D is rated for 500 V (matching the original FDD5N50UTF_WS), while TK4P55D is rated for 550 V. The TK4P55D also provides slightly lower on-state resistance (1.88 Ω versus 2 Ω). Both devices share identical current rating (4 A), power dissipation (80 W), and package configuration. Selection between these two depends on application voltage requirements and design margin considerations.

Q: Are the substitute parts available in the same package as the original FDD5N50UTF_WS?

A: Yes. All substitute parts are housed in the TO-252-3 DPAK (2 Leads + Tab) surface mount package, identical to the original FDD5N50UTF_WS. This ensures mechanical and thermal compatibility with existing PCB layouts and thermal management designs.

Q: What is the significance of the FDD5N50UTF_WS being classified as obsolete?

A: Obsolete status indicates the part is no longer manufactured by onsemi and is no longer supported for new designs. Existing inventory may be available through authorized distributors, but long-term supply cannot be guaranteed. The identified substitute parts from Toshiba are active products with ongoing manufacturing support, ensuring reliable supply for both new designs and legacy system maintenance.

Q: Do the substitute parts meet the same regulatory and compliance standards as the original?

A: The substitute parts are RoHS Compliant, which exceeds the REACH Unaffected status of the original FDD5N50UTF_WS. Both substitute parts carry identical ECCN (EAR99) and HTSUS (8541.29.0095) classifications, ensuring regulatory alignment for export and trade purposes. Moisture Sensitivity Level (MSL 1 — Unlimited) is identical across all three devices.

Q: Can the TK4P55D be used in applications originally designed for 500 V operation?

A: Yes. The TK4P55D is rated for 550 V, which exceeds the 500 V requirement of the original FDD5N50UTF_WS. This higher voltage rating provides additional design margin and is suitable for applications subject to voltage transients or overvoltage conditions. No circuit modifications are required; the device operates safely within the original 500 V operating envelope.

Q: What are the thermal implications of using a substitute with higher power dissipation rating?

A: Both substitute parts (TK4P50D and TK4P55D) are rated for 80 W power dissipation, compared to 40 W for the original FDD5N50UTF_WS. This doubled thermal capability allows for higher continuous current operation or improved thermal margin in existing designs. Existing thermal management solutions (heatsinks, PCB copper area) designed for the original 40 W device will provide enhanced thermal performance with the substitute parts.