BD680AS Equivalent & Substitute Parts

Part Overview

The BD680AS is a PNP Darlington bipolar junction transistor manufactured by onsemi, rated for 80 V collector-emitter breakdown voltage and 4 A maximum collector current. This device is packaged in TO-126-3 (TO-225AA) through-hole configuration with a maximum power dissipation of 14 W. The BD680AS is classified as obsolete, making equivalent substitute parts necessary for ongoing design support and procurement continuity. Alternative parts with matching or superior electrical specifications and compatible packaging enable direct replacement in existing applications.

Substiute Parts

BD680AS

onsemiIn Stock: 1152BD680AS Datasheet

Current PartRFQ

MJE703G

onsemiIn Stock: 2418MJE703G Datasheet

DirectRFQ

MJE702G

onsemiIn Stock: 37888MJE702G Datasheet

SimilarRFQ

BD680

STMicroelectronicsIn Stock: 8231BD680 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BD680AS is determined by equivalence in the following critical parameters: transistor type (PNP Darlington), maximum collector current (4 A), collector-emitter breakdown voltage (80 V), DC current gain (minimum 750), and through-hole mounting compatibility. Parts are grouped into two categories based on product status and packaging configuration:

Direct Electrical Equivalents (Obsolete Status): MJE703G and MJE702G maintain identical maximum collector current (4 A) and breakdown voltage (80 V) specifications. Both devices feature increased maximum power dissipation (40 W versus 14 W) and extended operating temperature ranges (-55°C to 150°C), providing enhanced thermal performance. These parts are compatible with TO-126-3 packaging and meet ROHS3 compliance requirements.

Active Product Alternative (Different Packaging): BD680 manufactured by STMicroelectronics is an active product with matching electrical specifications (4 A, 80 V, 750 hFE minimum) but supplied in SOT-32-3 package configuration rather than TO-126-3. This part provides long-term availability and equivalent electrical performance for applications where package form factor can be accommodated.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Same Package): MJE703G and MJE702G are suitable direct substitutes for BD680AS applications. Both parts maintain TO-126-3 package compatibility and satisfy ROHS3 compliance requirements. MJE703G and MJE702G provide superior thermal performance with 40 W maximum power dissipation compared to the 14 W rating of BD680AS, enabling operation in higher power applications without modification. Both obsolete parts share equivalent electrical specifications with the main part across critical parameters including collector current, breakdown voltage, and current gain.

For Long-Term Availability: BD680 manufactured by STMicroelectronics is an active product offering equivalent electrical performance (4 A, 80 V, 750 hFE minimum) with ROHS3 compliance. The primary distinction is packaging configuration: BD680 is supplied in SOT-32-3 format rather than TO-126-3. Selection of BD680 requires board-level accommodation of the alternative package footprint but provides ongoing procurement availability and manufacturer support.

Compliance Considerations: All substitute parts maintain ROHS3 compliance and REACH unaffected status, matching the regulatory profile of the original BD680AS. Moisture sensitivity level (MSL) is rated as 1 (Unlimited) for BD680AS and MJE702G, indicating no moisture-related handling restrictions.

Frequently Asked Questions (FAQ)

Q: Can MJE703G or MJE702G be used as direct replacements for BD680AS in existing designs?

A: Yes. MJE703G and MJE702G are electrically equivalent to BD680AS with identical maximum collector current (4 A), collector-emitter breakdown voltage (80 V), and DC current gain specifications (750 minimum). Both parts are packaged in TO-126-3 configuration, enabling direct board-level substitution without layout modification. The increased power dissipation rating (40 W versus 14 W) provides additional thermal margin.

Q: What is the primary difference between MJE703G and MJE702G?

A: Both parts share identical maximum ratings and package configuration. The distinction lies in Vce saturation specifications: MJE703G is rated at 2.8 V (40 mA, 2 A) while MJE702G is rated at 2.5 V (30 mA, 1.5 A). MJE702G exhibits lower saturation voltage at reduced base and collector currents. Selection depends on specific circuit bias point requirements.

Q: Why is BD680 (STMicroelectronics) listed as an alternative if the package differs?

A: BD680 is an active product with equivalent electrical specifications, providing long-term procurement availability. The SOT-32-3 package differs from TO-126-3, requiring board redesign for implementation. This alternative is suitable for new designs or redesign efforts where package accommodation is feasible.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. BD680AS, MJE703G, MJE702G, and BD680 are all ROHS3 compliant and REACH unaffected, maintaining regulatory equivalence across the substitute group.

Q: What is the impact of the higher power rating on MJE703G and MJE702G?

A: The 40 W maximum power dissipation of MJE703G and MJE702G (compared to 14 W for BD680AS) indicates superior thermal performance and thermal management capability. This allows operation at higher power levels without exceeding junction temperature limits. In applications operating within the 14 W envelope of BD680AS, the higher rating provides additional safety margin.

Q: Can these parts be used interchangeably in high-temperature applications?

A: MJE703G and MJE702G specify operating temperature range of -55°C to 150°C, providing extended low-temperature capability compared to BD680AS (150°C maximum only). For applications requiring operation below ambient temperature, MJE703G or MJE702G are preferred. All parts support 150°C maximum junction temperature operation.