FDPF8N50NZF N-Channel 500V 7A MOSFET Equivalent & Substitute Parts

Part Overview

The FDPF8N50NZF is an N-Channel 500V 7A MOSFET manufactured by onsemi in the UniFET-II™ series, housed in a TO-220F-3 through-hole package. This device is rated for 40W power dissipation and operates across a temperature range of -55°C to 150°C. The part is currently obsolete, making identification of functionally equivalent alternatives necessary for ongoing design support, maintenance, and production continuity. Substitute parts must maintain compatibility with existing PCB layouts, thermal management requirements, and electrical performance specifications.

Substiute Parts

FDPF8N50NZF

onsemiIn Stock: 2160FDPF8N50NZF Datasheet

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R5007FNX

Rohm SemiconductorIn Stock: 1211R5007FNX Datasheet

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TK7A45DA(STA4,Q,M)

Toshiba Semiconductor and StorageIn Stock: 735TK7A45DA(STA4,Q,M) Datasheet

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TK7A55D(STA4,Q,M)

Toshiba Semiconductor and StorageIn Stock: 990TK7A55D(STA4,Q,M) Datasheet

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TK8A45D(STA4,Q,M)

Toshiba Semiconductor and StorageIn Stock: 1012TK8A45D(STA4,Q,M) Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the FDPF8N50NZF is determined by strict alignment of electrical and mechanical parameters. The primary substitution criteria are:

Critical Parameters for Substitution:

• FET Type: N-Channel topology
• Drain to Source Voltage (Vdss): Minimum 500V to maintain voltage rating compatibility
• Continuous Drain Current (Id): Minimum 7A to support load requirements
• Package Type: TO-220-3 through-hole configuration for PCB compatibility
• Power Dissipation: Minimum 40W to ensure thermal performance equivalence
• Operating Temperature: Support for -55°C to 150°C range

Secondary Parameters for Optimization:

• On-State Resistance (Rds On): Lower values reduce conduction losses
• Gate Charge (Qg): Lower values reduce switching losses and gate drive requirements
• Gate Threshold Voltage (Vgs(th)): Consistency ensures compatible gate drive circuits

Substitute parts are grouped based on whether they meet or exceed the critical parameters while maintaining through-hole TO-220 package compatibility. Parts that fall below the specified voltage, current, or power ratings are not suitable substitutes.

Parameter Comparison

Engineering Selection Recommendations

R5007FNX (Rohm Semiconductor)

The R5007FNX is a direct electrical equivalent with matching 500V Vdss and 7A Id ratings. It maintains the 40W power dissipation specification and is RoHS3 compliant. The part is currently in active production status, ensuring long-term availability. The TO-220FM package is mechanically compatible with TO-220-3 through-hole layouts. On-state resistance is slightly elevated at 1.3Ω compared to 1.0Ω, resulting in marginally higher conduction losses. Operating temperature range extends to -40°C minimum, which is acceptable for most applications requiring -55°C operation only in edge cases. This part is suitable for direct substitution in applications where the slightly higher Rds On is acceptable.

TK7A45DA (Toshiba Semiconductor and Storage)

The TK7A45DA operates at 450V Vdss and 6.5A Id, both below the original specification. This part does not meet the critical voltage and current requirements and is not suitable as a direct substitute for applications requiring full 500V/7A performance. However, it may be considered for applications with reduced voltage or current headroom. The part is active and RoHS3 compliant. The TO-220SIS package is mechanically compatible with through-hole layouts.

TK7A55D (Toshiba Semiconductor and Storage)

The TK7A55D exceeds the voltage specification at 550V Vdss while maintaining the 7A Id rating. This part is suitable for applications where higher voltage margin is beneficial. Power dissipation is rated at 35W, which is 5W below the original specification. The part is active and RoHS3 compliant. The TO-220SIS package is mechanically compatible. This part is suitable for substitution in applications where the reduced power dissipation rating does not constrain thermal design.

TK8A45D (Toshiba Semiconductor and Storage)

The TK8A45D operates at 450V Vdss, below the original 500V specification, and therefore does not meet critical voltage requirements for direct substitution. The 8A Id rating exceeds the original 7A specification. Power dissipation is 35W, below the original 40W. This part is not suitable as a direct substitute for applications requiring full 500V operation. The part is active and RoHS3 compliant.

Recommended Selection Criteria:

For applications requiring full 500V/7A performance with minimal design changes, the R5007FNX is the primary substitute. For applications with voltage or current margin, the TK7A55D provides higher voltage headroom. All substitute parts are RoHS3 compliant and available from active production, ensuring supply chain continuity. Package variants (TO-220FM, TO-220SIS) are mechanically compatible with standard TO-220-3 through-hole PCB layouts.

Frequently Asked Questions (FAQ)

Q: Can the R5007FNX directly replace the FDPF8N50NZF without PCB modifications?

A: Yes. The R5007FNX maintains the same electrical ratings (500V, 7A, 40W) and uses a TO-220FM package that is mechanically compatible with TO-220-3 through-hole footprints. No PCB layout changes are required.

Q: Why are the Toshiba TK7A45DA and TK8A45D not recommended as direct substitutes?

A: The TK7A45DA operates at 450V, which is 50V below the original 500V specification. The TK8A45D also operates at 450V. These parts do not meet the critical voltage requirement and are unsuitable for applications requiring the full 500V rating. They may be considered only for applications with reduced voltage requirements.

Q: What is the significance of the different Rds On values among substitute parts?

A: On-state resistance directly affects conduction losses and heat generation. The FDPF8N50NZF specifies 1.0Ω at 3.5A/10V. The R5007FNX at 1.3Ω will generate approximately 30% more conduction loss under identical operating conditions. The TK8A45D at 0.9Ω generates less loss. Selection depends on thermal budget and efficiency requirements.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All listed substitute parts are RoHS3 compliant, matching the compliance status of the original FDPF8N50NZF.

Q: What is the difference between TO-220F-3, TO-220FM, and TO-220SIS packages?

A: All three are TO-220 through-hole packages with three leads (Gate, Drain, Source). The primary differences are in mechanical details and thermal characteristics. TO-220FM and TO-220SIS are mechanically compatible with TO-220-3 footprints for PCB mounting. Verify specific thermal interface requirements with the component datasheet if heat sink mounting is required.

Q: Can the TK7A55D be used in place of the FDPF8N50NZF?

A: The TK7A55D exceeds the voltage specification (550V vs. 500V) and maintains the current rating (7A). However, power dissipation is rated at 35W versus 40W. This part is suitable if the thermal design does not require the full 40W rating. The higher voltage rating provides additional margin for voltage transients.

Q: What is the operating temperature range compatibility?

A: The FDPF8N50NZF operates from -55°C to 150°C. The R5007FNX operates from -40°C to 150°C, which is acceptable for most applications. The Toshiba parts (TK7A45DA, TK7A55D, TK8A45D) all support -55°C to 150°C, matching the original specification.

Q: Are there any gate drive circuit modifications needed when substituting parts?

A: Gate threshold voltages vary slightly among parts (5.0V for FDPF8N50NZF, 4.0V for R5007FNX, 4.4V for Toshiba parts). Existing gate drive circuits designed for the original part will function with substitutes, though gate charge differences may affect switching speed. Verify gate drive voltage and current capability with the substitute part datasheet.