BFL4026 N-Channel MOSFET 900V 3.5A Equivalent & Substitute Parts

Part Overview

The BFL4026 is an N-Channel MOSFET manufactured by onsemi, rated for 900V drain-to-source voltage with 3.5A continuous drain current at 25°C. The device is packaged in a Through Hole TO-220FI(LS) configuration and is designed for high-voltage switching applications. The BFL4026 is classified as obsolete, making identification of equivalent and substitute parts necessary for ongoing design support, maintenance, and production continuity. Substitute parts must maintain electrical compatibility across voltage ratings, current handling, and thermal characteristics while accommodating available packaging options.

Substiute Parts

BFL4026

onsemiIn Stock: 1194BFL4026 Datasheet

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2SK3798(STA4,Q,M)

Toshiba Semiconductor and StorageIn Stock: 11602SK3798(STA4,Q,M) Datasheet

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STF5N95K3

STMicroelectronicsIn Stock: 2359STF5N95K3 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the BFL4026 are selected based on the following critical electrical and mechanical parameters:

Voltage Rating Compatibility: Substitute parts must maintain a Drain to Source Voltage (Vdss) rating equal to or greater than 900V to ensure safe operation in the original application circuit.

Current Handling: Substitute parts must support continuous drain current (Id) at or above 3.5A at 25°C to meet or exceed the original device performance.

On-State Resistance (Rds On): Substitute parts must maintain Rds On values at or below the original specification to ensure comparable power dissipation and thermal performance.

Gate Drive Voltage: Substitute parts must operate with the same 10V gate drive voltage specification to maintain compatibility with existing gate driver circuits.

Package Compatibility: Substitute parts must use Through Hole TO-220 family packaging to ensure mechanical fit within existing PCB layouts and thermal management solutions.

Operating Temperature Range: Substitute parts must support the full -55°C to 150°C operating temperature range to maintain reliability across all environmental conditions.

Moisture Sensitivity: Substitute parts must maintain MSL 1 (Unlimited) classification to ensure handling and storage compatibility.

The two substitute parts identified—2SK3798(STA4,Q,M) from Toshiba Semiconductor and Storage and STF5N95K3 from STMicroelectronics—meet all critical substitution criteria while offering active product status and enhanced compliance certifications.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Electrical and Mechanical Compatibility):

The 2SK3798(STA4,Q,M) from Toshiba Semiconductor and Storage provides the closest electrical match to the BFL4026. Both devices share identical 900V Vdss ratings and equivalent Rds On specifications at 10V gate drive. The Toshiba substitute offers 4A continuous drain current, exceeding the original 3.5A specification. The device maintains full compatibility with existing TO-220-3 Through Hole PCB layouts and thermal management infrastructure. The 2SK3798(STA4,Q,M) is classified as Active product status with ROHS3 compliance, ensuring long-term availability and regulatory alignment.

For Enhanced Performance and Compliance:

The STF5N95K3 from STMicroelectronics represents an alternative with superior electrical characteristics and enhanced compliance certifications. This device features a 950V Vdss rating, providing additional voltage margin over the original 900V specification. The STF5N95K3 delivers 4A continuous drain current with equivalent 3.5 Ohm Rds On performance. The SuperMESH3™ technology platform reduces gate charge to 19 nC compared to the original 33 nC, resulting in lower switching losses and improved thermal efficiency. Input capacitance is reduced to 460 pF, enabling faster switching transitions. The STF5N95K3 maintains full operating temperature range compatibility (-55°C to 150°C) and is ROHS3 compliant with REACH Unaffected status. This device is suitable for applications requiring enhanced performance margins and modern compliance certifications.

Compliance and Regulatory Considerations:

Both substitute parts maintain MSL 1 (Unlimited) moisture sensitivity classification, ensuring compatibility with standard component handling and storage procedures. The 2SK3798(STA4,Q,M) and STF5N95K3 are both classified as ROHS3 compliant, meeting current environmental and hazardous substance restrictions. The STF5N95K3 carries REACH Unaffected status, matching the original BFL4026 regulatory profile. Both substitutes are assigned ECCN EAR99 and HTSUS 8541.29.0095 classifications, maintaining consistency with the original device for export and tariff purposes.

Frequently Asked Questions (FAQ)

Q: Can the 2SK3798(STA4,Q,M) be used as a direct replacement for the BFL4026 in existing designs?

A: Yes. The 2SK3798(STA4,Q,M) maintains identical 900V Vdss and 10V gate drive specifications. Both devices use TO-220-3 Through Hole packaging with equivalent pinout and thermal characteristics. The Toshiba substitute provides 4A continuous drain current, exceeding the original 3.5A specification. No circuit modifications are required for electrical or mechanical compatibility.

Q: What are the key differences between the 2SK3798(STA4,Q,M) and STF5N95K3 substitutes?

A: The primary differences are voltage rating, gate charge, and input capacitance. The STF5N95K3 offers 950V Vdss compared to 900V for both the original and Toshiba substitute, providing additional voltage margin. The STF5N95K3 reduces gate charge to 19 nC and input capacitance to 460 pF, compared to 33 nC and 650 pF for the BFL4026. These reductions result in lower switching losses and faster switching transitions. Both devices maintain equivalent Rds On performance and full operating temperature range compatibility.

Q: Are both substitute parts available in the same packaging as the BFL4026?

A: Yes. Both the 2SK3798(STA4,Q,M) and STF5N95K3 use TO-220-3 Full Pack Through Hole configuration, matching the original BFL4026 package specification. Both devices are mechanically compatible with existing PCB layouts and thermal management solutions designed for the original component.

Q: What is the operating temperature range for each substitute part?

A: The 2SK3798(STA4,Q,M) supports operation up to 150°C junction temperature. The STF5N95K3 maintains the full -55°C to 150°C operating temperature range, matching the original BFL4026 specification. Both devices are suitable for applications requiring extended temperature operation.

Q: Do the substitute parts meet current regulatory compliance requirements?

A: Yes. Both the 2SK3798(STA4,Q,M) and STF5N95K3 are ROHS3 compliant. The STF5N95K3 carries REACH Unaffected status, matching the original BFL4026 regulatory profile. Both devices maintain MSL 1 (Unlimited) moisture sensitivity classification and are assigned identical ECCN EAR99 and HTSUS 8541.29.0095 classifications as the original component.

Q: What is the product status for each substitute part?

A: Both substitute parts are classified as Active product status. The 2SK3798(STA4,Q,M) from Toshiba Semiconductor and Storage and the STF5N95K3 from STMicroelectronics are in current production with established supply chains. This contrasts with the original BFL4026, which is classified as Obsolete and subject to limited availability.

Q: How do the gate charge specifications affect circuit design?

A: Gate charge (Qg) determines the energy required to switch the MOSFET on and off. The BFL4026 requires 33 nC at 10V gate drive. The 2SK3798(STA4,Q,M) reduces this to 26 nC, while the STF5N95K3 further reduces it to 19 nC. Lower gate charge results in reduced switching losses and improved thermal efficiency. Existing gate driver circuits designed for the BFL4026 will operate with either substitute without modification, as both devices maintain the same 10V gate drive voltage specification.

Q: What is the significance of input capacitance (Ciss) differences between the parts?

A: Input capacitance affects switching speed and gate driver current requirements. The BFL4026 has 650 pF input capacitance at 30V. The 2SK3798(STA4,Q,M) increases this to 800 pF at 25V, while the STF5N95K3 reduces it to 460 pF at 25V. Lower input capacitance enables faster switching transitions and reduces gate driver stress. Existing gate driver circuits will function with either substitute, though the STF5N95K3 offers improved switching performance characteristics.