STF5N52U N-Channel MOSFET 525V 4.4A Equivalent & Substitute Parts

Part Overview

The STF5N52U is an N-Channel MOSFET manufactured by STMicroelectronics, rated for 525V drain-to-source voltage with 4.4A continuous drain current at 25°C. This device is packaged in a Through Hole TO-220FP configuration and is designed for high-voltage switching applications. The STF5N52U is classified as obsolete, making identification of equivalent and substitute parts essential for ongoing design support, maintenance, and production continuity. Substitute parts must maintain electrical compatibility across voltage, current, and thermal specifications while accommodating packaging variations.

Substiute Parts

STF5N52U

STMicroelectronicsIn Stock: 15272STF5N52U Datasheet

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2SK3199

Sanken Electric USA Inc.In Stock: 20572SK3199 Datasheet

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TK4A53D(STA4,Q,M)

Toshiba Semiconductor and StorageIn Stock: 737TK4A53D(STA4,Q,M) Datasheet

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TK5A55D(STA4,Q,M)

Toshiba Semiconductor and StorageIn Stock: 1100TK5A55D(STA4,Q,M) Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the STF5N52U is determined by the following critical electrical and mechanical parameters:

Voltage Rating (Vdss): Substitute parts must equal or exceed 525V to maintain voltage margin in high-voltage applications. Parts rated at 500V or 550V are acceptable within standard design tolerances.

Continuous Drain Current (Id): Substitute parts must support the application's current requirements. The STF5N52U operates at 4.4A; substitutes rated at 4A or higher are electrically compatible.

On-State Resistance (Rds On): Substitute parts must maintain comparable on-state resistance to ensure thermal performance and switching efficiency. Values at or below 1.7Ohm are acceptable.

Gate Threshold Voltage (Vgs(th)): Substitute parts must have compatible gate threshold voltages (4.0V to 4.5V range) to ensure proper gate drive compatibility.

Power Dissipation: Substitute parts must support thermal loads equivalent to or greater than 25W to prevent thermal runaway in the application.

Mounting and Packaging: All substitute parts are Through Hole mounted in TO-220 package variants (TO-220F, TO-220FP, TO-220SIS), ensuring mechanical compatibility with existing PCB layouts.

Compliance: All substitute parts maintain RoHS compliance and EAR99 export classification consistent with the original part.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: TK5A55D(STA4,Q,M) (Toshiba)

The TK5A55D is the recommended primary substitute for the STF5N52U. This part exceeds the voltage specification (550V vs. 525V), supports equivalent current ratings (5A vs. 4.4A), and maintains comparable on-state resistance (1.7Ohm). The TK5A55D is classified as Active with ROHS3 compliance, ensuring long-term availability and regulatory alignment. Gate threshold voltage (4.4V) and input capacitance (540 pF) are within acceptable operating margins. Power dissipation capability (35W) exceeds the original specification, providing thermal headroom. Inventory availability (1,048 units) supports production requirements.

Secondary Substitute: TK4A53D(STA4,Q,M) (Toshiba)

The TK4A53D provides an alternative with matched voltage rating (525V) and acceptable current specification (4A). On-state resistance (1.7Ohm @ 2A) is slightly elevated but remains within acceptable limits for most applications. This part is Active with RoHS compliance and offers higher power dissipation (35W). Gate threshold voltage (4.4V @ 1mA) ensures compatible gate drive characteristics. Inventory (633 units) is available for production support.

Tertiary Substitute: 2SK3199 (Sanken Electric USA Inc.)

The 2SK3199 is suitable for applications where voltage margin can accommodate a 500V rating (25V below the original specification). This part offers superior current capability (5A) and maintains equivalent on-state resistance (1.5Ohm @ 2.5A). The device is Active with RoHS compliance and provides higher power dissipation (30W). Gate threshold voltage (4V @ 1mA) is compatible with standard gate drive circuits. Inventory (2,000 units) provides strong supply availability. Use this substitute only when the application voltage ceiling does not exceed 500V.

Compliance and Availability Considerations

All three substitute parts maintain RoHS compliance and EAR99 export classification. The Toshiba devices (TK4A53D and TK5A55D) are preferred for new designs due to Active product status and ROHS3 compliance. The STF5N52U's obsolete status necessitates transition to one of these active alternatives for long-term supply chain stability.

Frequently Asked Questions (FAQ)

Q: Can the TK5A55D directly replace the STF5N52U in existing designs?

A: Yes. The TK5A55D meets or exceeds all critical electrical parameters: voltage rating (550V vs. 525V), current capability (5A vs. 4.4A), and on-state resistance (1.7Ohm vs. 1.5Ohm). The TO-220SIS package is mechanically compatible with TO-220FP layouts. Gate threshold voltage (4.4V) matches the original specification. No circuit modifications are required.

Q: What is the voltage margin difference between the STF5N52U (525V) and 2SK3199 (500V)?

A: The 2SK3199 operates 25V below the original specification. This 4.8% reduction in voltage rating is acceptable for applications with design margins exceeding 25V. For circuits operating near the 525V limit, use the TK5A55D (550V) or TK4A53D (525V) instead.

Q: Are there package compatibility issues between TO-220FP, TO-220F, and TO-220SIS?

A: All three package variants are Through Hole TO-220 configurations with identical pin assignments and PCB footprints. TO-220FP, TO-220F, and TO-220SIS are mechanically interchangeable on standard TO-220 PCB layouts. Verify thermal management provisions, as package variants may have different thermal characteristics.

Q: Which substitute part has the lowest on-state resistance?

A: The STF5N52U and 2SK3199 both specify 1.5Ohm on-state resistance. The Toshiba devices (TK4A53D and TK5A55D) specify 1.7Ohm. For applications requiring minimum conduction losses, the 2SK3199 or original STF5N52U provide superior performance. However, the 0.2Ohm difference is negligible in most high-voltage switching applications.

Q: What is the gate charge difference between the main part and substitutes?

A: The STF5N52U specifies 16.9 nC gate charge at 10V. The Toshiba devices (TK4A53D and TK5A55D) specify 11 nC, representing a 35% reduction. Lower gate charge reduces gate drive power requirements and improves switching speed. The 2SK3199 gate charge specification is not provided in the available data.

Q: Are all substitute parts RoHS compliant?

A: Yes. The STF5N52U is ROHS3 compliant. The TK5A55D is ROHS3 compliant. The TK4A53D and 2SK3199 are RoHS compliant. All parts meet regulatory requirements for lead-free manufacturing and hazardous substance restrictions.

Q: Which substitute offers the best thermal performance?

A: The TK4A53D and TK5A55D both specify 35W maximum power dissipation, compared to 25W for the STF5N52U. This 40% increase in thermal capacity provides improved thermal margin in high-power applications. The 2SK3199 specifies 30W, offering a 20% improvement over the original part.

Q: What is the current availability status of each substitute?

A: TK5A55D: 1,048 units in stock. TK4A53D: 633 units in stock. 2SK3199: 2,000 units in stock. All parts are available for immediate procurement. The 2SK3199 offers the highest inventory level for high-volume production requirements.