BUL146 Equivalent & Substitute Parts

Part Overview

The BUL146 is an NPN bipolar junction transistor manufactured by onsemi, rated for 400 V collector-emitter breakdown voltage and 6 A maximum collector current in a TO-220 through-hole package. Designed for switchmode applications, this component delivers 100 W maximum power dissipation with a 14 MHz transition frequency. The BUL146 is classified as obsolete, necessitating identification of active equivalent parts for new designs and ongoing production requirements. Substitute parts must maintain electrical compatibility across voltage, current, and thermal operating ranges while accommodating modern supply chain availability.

Substiute Parts

BUL146

onsemiIn Stock: 3721BUL146 Datasheet

Current PartRFQ

BUJ105A,127

WeEn SemiconductorsIn Stock: 835BUJ105A,127 Datasheet

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BUL138

STMicroelectronicsIn Stock: 9620BUL138 Datasheet

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ST13007

STMicroelectronicsIn Stock: 1296ST13007 Datasheet

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ST13007D

STMicroelectronicsIn Stock: 680301ST13007D Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the BUL146 is determined by the following critical parameters:

Mandatory Compatibility Criteria:

• Transistor Type: NPN configuration required
• Voltage Rating: Minimum 400 V collector-emitter breakdown voltage
• Current Rating: Minimum 6 A collector current capacity
• Package: TO-220-3 through-hole configuration
• Mounting: Through-hole compatibility with existing PCB layouts

Secondary Compatibility Factors:

• Operating temperature range must encompass or exceed -65°C to 150°C
• Power dissipation capability of 80 W or greater
• Saturation voltage characteristics within acceptable switching performance parameters

The substitute parts identified below satisfy these mandatory criteria while offering active product status and improved compliance certifications compared to the obsolete BUL146.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: ST13007D

The ST13007D represents the optimal substitute for the BUL146 in new designs and production transitions. This part maintains the 400 V voltage rating and exceeds the 6 A current requirement with an 8 A maximum rating. The ST13007D carries active product status with ROHS3 compliance and REACH unaffected certification, ensuring long-term supply chain viability and regulatory alignment. Inventory availability of 680,200 units provides supply security for volume production.

Secondary Substitute: ST13007

The ST13007 offers equivalent electrical performance to the ST13007D with identical voltage and current ratings. Active product status and ROHS3 compliance support modern manufacturing requirements. Lower inventory levels (1,218 units) compared to ST13007D may impact availability for high-volume applications.

Alternative Substitute: BUJ105A,127

The BUJ105A,127 from WeEn Semiconductors provides 8 A current capacity and 400 V voltage rating with RoHS compliance. This part accommodates applications requiring higher current headroom. Packaging in tube format and lower inventory (743 units) may influence procurement decisions for specific production scenarios.

Conditional Substitute: BUL138

The BUL138 maintains 400 V voltage compatibility but provides only 5 A maximum collector current, falling below the BUL146 specification. This part is suitable only for applications where the actual operating current remains below 5 A. ROHS3 compliance and high inventory (9,582 units) support availability-constrained situations with verified current requirements.

Frequently Asked Questions (FAQ)

Q: Can the BUL138 directly replace the BUL146 in all applications?

A: No. The BUL138 maximum collector current rating of 5 A is below the BUL146 specification of 6 A. Substitution is valid only when circuit analysis confirms actual operating current remains below 5 A throughout all operating conditions.

Q: What is the primary advantage of ST13007D over the original BUL146?

A: The ST13007D maintains identical voltage and thermal ratings while providing 8 A current capacity versus 6 A for the BUL146. Active product status ensures ongoing availability, and ROHS3 compliance satisfies modern regulatory requirements. The BUL146 is obsolete and no longer manufactured.

Q: Are all substitute parts available in the same TO-220-3 package?

A: Yes. All identified substitutes use the TO-220-3 through-hole package, enabling direct PCB layout compatibility. The BUJ105A,127 is supplied in tube packaging format, while other parts are available in tube packaging as well.

Q: What is the operating temperature range for substitute parts?

A: All substitute parts support a maximum junction temperature of 150°C. The BUL146 specifies -65°C to 150°C; substitute parts are rated to 150°C maximum. Verify minimum operating temperature requirements for your specific application, as some substitutes may not specify the -65°C lower limit.

Q: How do saturation voltage characteristics differ between the BUL146 and substitutes?

A: Saturation voltage varies across the part family. The BUL146 specifies 700 mV at 600 mA base current and 3 A collector current. The ST13007D specifies 2 V at 2 A base current and 8 A collector current. The BUL138 specifies 700 mV at 1 A base current and 5 A collector current. Circuit performance may differ; thermal design and switching characteristics require evaluation for specific applications.

Q: Which substitute offers the best long-term supply availability?

A: The ST13007D provides the strongest supply position with 680,200 units in stock and active product status from STMicroelectronics, a major semiconductor manufacturer with established distribution networks.

Q: Are there compliance differences between the BUL146 and substitute parts?

A: Yes. The BUL146 is RoHS non-compliant. All substitute parts carry RoHS compliance certifications (ROHS3 or equivalent). For applications subject to RoHS regulations, substitution is mandatory. All parts share identical ECCN (EAR99) and HTSUS (8541.29.0095) classifications.