BD680AG Equivalent & Substitute Parts

Part Overview

The BD680AG is a PNP Darlington bipolar junction transistor manufactured by onsemi, rated for 80 V collector-emitter breakdown voltage and 4 A maximum collector current in a TO-126 through-hole package. This device is classified as obsolete, making identification of equivalent and substitute parts necessary for ongoing design support, maintenance, and production continuity. The BD680AG delivers 40 W maximum power dissipation and operates across a temperature range of -55°C to 150°C (TJ).

Substiute Parts

BD680AG

onsemiIn Stock: 834BD680AG Datasheet

Current PartRFQ

MJE703G

onsemiIn Stock: 2418MJE703G Datasheet

DirectRFQ

BD680

STMicroelectronicsIn Stock: 8231BD680 Datasheet

UpgradeRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the BD680AG is determined by strict equivalence across the following critical parameters:

Mandatory Matching Criteria:

• Transistor Type: PNP - Darlington configuration
• Current - Collector (Ic) (Max): 4 A minimum
• Voltage - Collector Emitter Breakdown (Max): 80 V minimum
• Power - Max: 40 W minimum
• DC Current Gain (hFE) (Min): 750 or greater
• Operating Temperature Range: -55°C to 150°C or broader
• Mounting Type: Through Hole
• Package / Case: TO-225AA or TO-126-3 compatible
• RoHS Status: ROHS3 Compliant

Substitute Categories:

Direct Equivalent (Same Manufacturer, Same Package): MJE703G meets all electrical and mechanical parameters with identical ratings across collector current, breakdown voltage, power dissipation, and current gain. Both devices are manufactured by onsemi in TO-126 packaging and maintain ROHS3 compliance.

Upgrade Alternative (Same Base Number, Different Manufacturer): BD680 manufactured by STMicroelectronics provides active product status with improved specifications in certain parameters while maintaining core electrical ratings. This device uses SOT-32-3 packaging, which is mechanically compatible with TO-126 applications in through-hole mounting contexts.

Parameter Comparison

Engineering Selection Recommendations

For Direct Substitution (Identical Electrical and Mechanical Performance):

The MJE703G is a direct equivalent to the BD680AG. Both devices are manufactured by onsemi, share identical electrical specifications across all critical parameters, and are packaged in TO-126 through-hole format. The MJE703G exhibits superior collector cutoff current performance (100µA versus 500µA), resulting in lower leakage characteristics. Both parts maintain ROHS3 compliance and REACH unaffected status. The MJE703G is suitable for applications requiring immediate replacement with no circuit redesign.

For Active Product Status and Long-Term Availability:

The BD680 manufactured by STMicroelectronics is classified as active product status, providing superior long-term availability and supply chain continuity compared to the obsolete BD680AG and MJE703G. This device maintains identical collector current, breakdown voltage, and power ratings. The BD680 is packaged in SOT-32-3 format, which is mechanically compatible with TO-126 through-hole mounting. The STMicroelectronics BD680 demonstrates improved saturation voltage performance (2.5V versus 2.8V at specified test conditions), indicating enhanced switching efficiency. This part is recommended for new designs and production runs requiring extended product lifecycle support.

Frequently Asked Questions (FAQ)

Q: Can the MJE703G directly replace the BD680AG without circuit modification?

A: Yes. The MJE703G meets all electrical and mechanical specifications of the BD680AG. Both devices are PNP Darlington transistors with 4 A collector current, 80 V breakdown voltage, 40 W power rating, and TO-126 through-hole packaging. Pin configuration and functional behavior are identical.

Q: What is the primary advantage of selecting the STMicroelectronics BD680 over the onsemi alternatives?

A: The STMicroelectronics BD680 carries active product status, ensuring ongoing manufacturing and supply availability. The onsemi BD680AG and MJE703G are classified as obsolete. Additionally, the BD680 exhibits lower saturation voltage (2.5V versus 2.8V), providing improved switching performance and reduced power dissipation in saturation mode.

Q: Are the TO-126 and SOT-32-3 packages mechanically interchangeable?

A: Both TO-126 and SOT-32-3 are through-hole packages with compatible pin configurations for this device category. Physical dimensions and lead spacing differ, but both are suitable for through-hole PCB mounting. Verify PCB footprint compatibility before substitution.

Q: Do all three parts meet current environmental compliance standards?

A: Yes. The BD680AG, MJE703G, and BD680 are all ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements for electronic component manufacturing and distribution.

Q: What is the significance of the collector cutoff current difference between BD680AG (500µA) and MJE703G (100µA)?

A: The MJE703G exhibits lower leakage current in the off state. This results in reduced standby power consumption and improved switching characteristics in applications where low leakage is critical. Both values remain within acceptable limits for standard switching applications.

Q: Which substitute part should be selected for a new product design?

A: The STMicroelectronics BD680 is recommended for new designs. Active product status ensures long-term availability, manufacturing consistency, and supply chain reliability. The improved saturation voltage performance provides additional design margin for switching applications.