BDX34B Equivalent & Substitute Parts

Part Overview

The BDX34B is a PNP Darlington bipolar junction transistor manufactured by onsemi, rated for 80 V collector-emitter breakdown voltage and 10 A maximum collector current in a TO-220 through-hole package. This device is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements. The BDX34B delivers 70 W maximum power dissipation with a minimum DC current gain of 750 at 3 A collector current and 3 V collector-emitter voltage.

Substiute Parts

BDX34B

onsemiIn Stock: 1434BDX34B Datasheet

Current PartRFQ

BDX34C

STMicroelectronicsIn Stock: 21382BDX34C Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BDX34B is determined by electrical and mechanical compatibility across the following critical parameters:

Electrical Compatibility Criteria:

• Transistor type must be PNP - Darlington
• Maximum collector current must equal or exceed 10 A
• Collector-emitter breakdown voltage must equal or exceed 80 V
• Vce saturation characteristics must match or improve upon 2.5 V @ 6 mA, 3 A
• DC current gain (hFE) must meet or exceed 750 @ 3 A, 3 V
• Maximum power dissipation must equal or exceed 70 W

Mechanical Compatibility Criteria:

• Package type must be TO-220-3
• Mounting configuration must be through-hole

The BDX34C from STMicroelectronics satisfies all substitution criteria, offering improved voltage rating (100 V versus 80 V) while maintaining identical current, power, and gain specifications.

Parameter Comparison

Engineering Selection Recommendations

The BDX34C from STMicroelectronics is the direct substitute for the obsolete BDX34B. Selection of the BDX34C is supported by the following factors:

Product Status: The BDX34B is classified as obsolete, whereas the BDX34C maintains active product status with established supply chains and manufacturing continuity.

Regulatory Compliance: The BDX34C is ROHS3 compliant, meeting current environmental and regulatory requirements. The BDX34B is RoHS non-compliant, presenting compliance challenges for new designs and applications subject to RoHS directives.

Electrical Performance: The BDX34C provides a 20 V increase in collector-emitter breakdown voltage (100 V versus 80 V) while maintaining identical current, power, and gain specifications. This enhanced voltage rating provides additional design margin without performance degradation.

Mechanical Compatibility: Both devices utilize identical TO-220-3 through-hole packaging, ensuring direct pin-compatible replacement without circuit board modifications.

Frequently Asked Questions (FAQ)

Q: Can the BDX34C directly replace the BDX34B in existing circuits?

A: Yes. The BDX34C is pin-compatible with the BDX34B in TO-220-3 configuration. All electrical parameters either match or exceed the BDX34B specifications, enabling direct substitution without circuit modifications.

Q: What is the primary difference between the BDX34B and BDX34C?

A: The BDX34C features a higher collector-emitter breakdown voltage rating of 100 V compared to the BDX34B at 80 V. All other electrical characteristics, including current, power, and gain specifications, remain identical. The BDX34C also maintains active product status and ROHS3 compliance.

Q: Why is the BDX34B classified as obsolete?

A: The BDX34B is no longer in active production. The BDX34C serves as the current production equivalent, offering improved regulatory compliance and sustained manufacturing support.

Q: Are there any thermal or mounting considerations when substituting the BDX34C for the BDX34B?

A: Both devices operate across the same temperature range (−65°C to 150°C) and utilize identical through-hole TO-220-3 packaging. Thermal management requirements remain unchanged, and existing heat sink designs are directly compatible.

Q: Does the BDX34C require different circuit design considerations?

A: No. The BDX34C maintains identical Vce saturation, DC current gain, and collector cutoff specifications. Circuit biasing, base drive requirements, and load calculations remain unchanged from the BDX34B design.

Q: What is the inventory status of the BDX34C?

A: The BDX34C is available with 21,370 pieces in stock as new original inventory, ensuring reliable supply for production requirements.