BD680 Equivalent & Substitute Parts

Part Overview

The BD680 is a PNP Darlington bipolar junction transistor (BJT) rated for 80 V collector-emitter breakdown voltage and 4 A maximum collector current. The device is designed for through-hole mounting in TO-126 package configuration and delivers 40 W maximum power dissipation. The onsemi BD680 is classified as obsolete, necessitating identification of functionally equivalent alternatives for ongoing production and maintenance applications. Substitute parts must maintain electrical and mechanical compatibility while meeting current component availability and compliance requirements.

Substiute Parts

BD680

onsemiIn Stock: 8238BD680 Datasheet

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BD680

STMicroelectronicsIn Stock: 8231BD680 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the BD680 is determined by strict equivalence across the following electrical and mechanical parameters:

Electrical Equivalence Criteria:

• Transistor type: PNP - Darlington configuration
• Maximum collector current: 4 A
• Maximum collector-emitter breakdown voltage: 80 V
• Vce saturation characteristics: 2.5V @ 30mA, 1.5A
• Maximum collector cutoff current: 500µA
• DC current gain (hFE): minimum 750 @ 1.5A, 3V
• Maximum power dissipation: 40 W

Mechanical Equivalence Criteria:

• Mounting type: Through Hole
• Package designation: TO-225AA or TO-126-3 compatible
• Moisture sensitivity level: 1 (Unlimited)

The STMicroelectronics BD680 (SOT-32-3 package variant) satisfies all electrical parameters and maintains through-hole mounting compatibility. The substitute part is classified as Active product status, ensuring ongoing availability and supply chain continuity.

Parameter Comparison

Engineering Selection Recommendations

The STMicroelectronics BD680 in SOT-32-3 package configuration is the direct functional equivalent for the obsolete onsemi BD680. Selection of the STMicroelectronics variant is supported by the following factors:

Product Status: The STMicroelectronics BD680 maintains Active product status, ensuring long-term component availability and supply chain reliability. The onsemi BD680 is classified as Obsolete, creating procurement risk for new production and field replacement applications.

Regulatory Compliance: The STMicroelectronics BD680 is ROHS3 Compliant, meeting current environmental and hazardous substance restrictions. The onsemi BD680 is RoHS non-compliant, presenting compliance barriers for applications subject to RoHS regulations.

Electrical Performance: All critical electrical parameters are identical between the two devices, including collector current rating (4 A), breakdown voltage (80 V), saturation characteristics, current gain, and power dissipation (40 W). Operating temperature compatibility is maintained within the specified range.

Mechanical Compatibility: Both devices employ through-hole mounting with equivalent package designations (TO-225AA, TO-126-3). Moisture sensitivity level is identical (MSL 1 - Unlimited), eliminating handling and storage requirement changes.

Regulatory Certifications: Both parts maintain REACH Unaffected status and EAR99 ECCN classification, with identical HTSUS coding (8541.29.0095).

Frequently Asked Questions (FAQ)

Q: Can the STMicroelectronics BD680 (SOT-32-3) be used as a direct replacement for the onsemi BD680 (TO-126)?

A: Yes. Both devices are electrically equivalent across all specified parameters: 4 A collector current, 80 V breakdown voltage, 40 W power dissipation, and identical saturation and gain characteristics. Both employ through-hole mounting with compatible package designations. The STMicroelectronics variant is the preferred selection due to Active product status and ROHS3 compliance.

Q: What is the difference between TO-126 and SOT-32-3 packages?

A: TO-126 and SOT-32-3 are both through-hole package designations for three-terminal devices. The package designation difference reflects manufacturer-specific nomenclature; both are mechanically and electrically compatible for the BD680 application. Pinout and lead spacing are equivalent.

Q: Why is the onsemi BD680 classified as Obsolete?

A: Obsolete status indicates the manufacturer has discontinued production and support for this component. This classification necessitates transition to active alternatives to ensure ongoing supply chain continuity and component availability for production and maintenance applications.

Q: Does the STMicroelectronics BD680 require different circuit design considerations?

A: No. The STMicroelectronics BD680 maintains identical electrical specifications across all critical parameters. Circuit design, biasing networks, and thermal management calculations remain unchanged from the onsemi BD680 design.

Q: What is the significance of ROHS3 compliance on the STMicroelectronics part?

A: ROHS3 compliance indicates the component meets current Restriction of Hazardous Substances regulations, restricting lead, cadmium, mercury, and other hazardous materials. This compliance is required for applications subject to environmental regulations in the European Union and other jurisdictions. The onsemi BD680 is RoHS non-compliant, creating regulatory barriers for new designs.

Q: Are there any thermal performance differences between the two BD680 variants?

A: No. Both devices are rated for 40 W maximum power dissipation and maintain equivalent thermal characteristics. The onsemi BD680 specifies -55°C to 150°C operating range; the STMicroelectronics variant specifies 150°C maximum junction temperature. Both are suitable for identical thermal management applications.

Q: Can inventory of onsemi BD680 components be used in new production?

A: Existing onsemi BD680 inventory can be used in applications where RoHS non-compliance is acceptable and component availability is not a constraint. For new production designs, transition to the STMicroelectronics BD680 is recommended to ensure long-term supply chain reliability and regulatory compliance.