BUD42DG Equivalent & Substitute Parts

Part Overview

The BUD42DG is an NPN bipolar junction transistor manufactured by onsemi, rated for 350 V collector-emitter breakdown voltage and 4 A maximum collector current in a surface mount DPAK package. This component is classified as obsolete, necessitating identification of functionally equivalent alternatives for ongoing design support and procurement continuity. Substitute parts must maintain electrical compatibility within the specified parameter ranges while accommodating modern active product availability.

Substiute Parts

BUD42DG

onsemiIn Stock: 681BUD42DG Datasheet

Current PartRFQ

BUJ103AD,118

WeEn SemiconductorsIn Stock: 3181BUJ103AD,118 Datasheet

SimilarRFQ

BUJ302AD,118

WeEn SemiconductorsIn Stock: 12420BUJ302AD,118 Datasheet

SimilarRFQ

BUJD103AD,118

WeEn SemiconductorsIn Stock: 966BUJD103AD,118 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the BUD42DG are selected based on the following electrical and mechanical compatibility criteria:

Primary Substitution Criteria:

• Transistor type: NPN
• Package: TO-252-3, DPAK (2 Leads + Tab), SC-63 surface mount
• Maximum collector current: 4 A or greater
• Collector-emitter breakdown voltage: 400 V or greater (exceeds 350 V minimum requirement)
• Moisture sensitivity level: 1 (Unlimited)

Substitute Parts Identified:

1. BUJ103AD,118 (WeEn Semiconductors) — Active product status, 400 V / 4 A rating, 80 W power dissipation, Tape & Reel packaging
2. BUJ302AD,118 (WeEn Semiconductors) — Active product status, 400 V / 4 A rating, 80 W power dissipation, Cut Tape & Digi-Reel packaging, ROHS3 compliant
3. BUJD103AD,118 (WeEn Semiconductors) — Active product status, 400 V / 4 A rating, 80 W power dissipation, Tape & Reel packaging

All substitute parts meet or exceed the electrical specifications of the BUD42DG while offering improved power handling (80 W vs. 25 W) and higher collector-emitter breakdown voltage (400 V vs. 350 V).

Parameter Comparison

Engineering Selection Recommendations

BUJ103AD,118 is suitable for applications requiring standard performance characteristics with RoHS compliance. This part maintains electrical parameters closely aligned with the BUD42DG while offering active product status and improved power dissipation capability. Tape & Reel packaging supports automated assembly processes.

BUJ302AD,118 provides enhanced DC current gain (25 @ 800 mA, 3 V) and ROHS3 compliance, making it appropriate for designs requiring higher gain performance. Cut Tape & Digi-Reel packaging accommodates both manual and automated procurement workflows. The higher collector cutoff current (250 mA) should be evaluated against circuit leakage requirements.

BUJD103AD,118 offers electrical characteristics most closely matching the BUD42DG baseline, with collector cutoff current and DC current gain parameters nearly identical to the original part. RoHS compliance and Tape & Reel packaging provide modern supply chain compatibility. This part is recommended for direct replacement in existing designs with minimal circuit re-evaluation.

All three substitute parts exceed the original 350 V breakdown voltage specification at 400 V, providing additional design margin. The increased power rating (80 W vs. 25 W) permits operation in higher thermal environments without performance degradation.

Frequently Asked Questions (FAQ)

Q: Can BUJ103AD,118, BUJ302AD,118, and BUJD103AD,118 be used interchangeably with BUD42DG?

A: All three parts are electrically compatible substitutes within the specified parameter ranges. They share identical collector current (4 A), collector-emitter breakdown voltage (400 V minimum), package type (TO-252-3 DPAK), and mounting configuration. Selection between them depends on specific application requirements regarding DC current gain, saturation voltage, and packaging format.

Q: What is the primary advantage of the substitute parts over the BUD42DG?

A: The substitute parts offer three key advantages: (1) active product status ensuring long-term availability, (2) increased power dissipation rating (80 W vs. 25 W), and (3) higher collector-emitter breakdown voltage (400 V vs. 350 V), providing additional design margin and thermal headroom.

Q: Are there compliance differences between the substitute parts?

A: BUJ103AD,118 and BUJD103AD,118 are RoHS compliant. BUJ302AD,118 is ROHS3 compliant and REACH affected. All parts carry MSL 1 (Unlimited) moisture sensitivity rating. Compliance selection depends on end-product regulatory requirements.

Q: How do the DC current gain specifications differ?

A: BUD42DG specifies 10 @ 2 A, 5 V. BUJ103AD,118 provides 13 @ 500 mA, 5 V. BUJ302AD,118 offers 25 @ 800 mA, 3 V. BUJD103AD,118 provides 11 @ 2 A, 5 V. Higher gain values reduce base drive requirements in switching applications.

Q: Which substitute part most closely matches the original BUD42DG specifications?

A: BUJD103AD,118 provides the closest electrical match, with collector cutoff current (100 µA) and DC current gain (11 @ 2 A, 5 V) nearly identical to the BUD42DG. This part is recommended for direct replacement in existing circuit designs.

Q: What packaging options are available for the substitute parts?

A: BUJ103AD,118 and BUJD103AD,118 are supplied in Tape & Reel format. BUJ302AD,118 is available in Cut Tape & Digi-Reel format. All maintain the same TO-252-3 DPAK physical package for PCB compatibility.

Q: Are the substitute parts suitable for high-temperature applications?

A: All substitute parts support maximum junction temperature of 150°C, matching the BUD42DG specification. The increased power rating (80 W) permits sustained operation at elevated temperatures without thermal derating.