BD680A Equivalent & Substitute Parts

Part Overview

The BD680A is a PNP Darlington bipolar junction transistor manufactured by STMicroelectronics, rated for 80 V collector-emitter breakdown voltage and 4 A maximum collector current in a Through Hole SOT-32-3 package. This component is classified as obsolete, necessitating identification of equivalent and substitute parts for ongoing design support and procurement continuity. Substitute parts must maintain electrical compatibility across critical parameters including voltage rating, current capacity, and DC current gain specifications.

Key Parameters

Parameter	Value	Unit
Transistor Type	PNP - Darlington	—
Current - Collector (Ic) (Max)	4	A
Voltage - Collector Emitter Breakdown (Max)	80	V
Power - Max	40	W
DC Current Gain (hFE) (Min)	750	—
Mounting Type	Through Hole	—
Operating Temperature (Max)	150	°C
RoHS Status	ROHS3 Compliant	—

Substitute Part Grouping Explanation

Substitution eligibility for the BD680A is determined by strict equivalence across the following parameters:

Primary Equivalence 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
Mounting Type: Through Hole
Operating Temperature: 150°C maximum junction temperature
RoHS Compliance: ROHS3 Compliant

Package Compatibility: Substitute parts must utilize compatible Through Hole packages (TO-225AA, TO-126-3, or SOT-32-3) to ensure mechanical fit in existing PCB layouts.

The BD680A, BD680, MJE703G, and MJE702G all satisfy these criteria and are therefore classified as direct substitutes or equivalents.

Parameter Comparison

Parameter	BD680A	BD680	MJE703G	MJE702G
Manufacturer	STMicroelectronics	STMicroelectronics	onsemi	onsemi
Product Status	Obsolete	Active	Obsolete	Obsolete
Transistor Type	PNP - Darlington	PNP - Darlington	PNP - Darlington	PNP - Darlington
Current - Collector (Ic) (Max)	4 A	4 A	4 A	4 A
Voltage - Collector Emitter Breakdown (Max)	80 V	80 V	80 V	80 V
Vce Saturation (Max) @ Ib, Ic	2.8V @ 40mA, 2A	2.5V @ 30mA, 1.5A	2.8V @ 40mA, 2A	2.5V @ 30mA, 1.5A
Current - Collector Cutoff (Max)	500µA	500µA	100µA	100µA
DC Current Gain (hFE) (Min) @ Ic, Vce	750 @ 2A, 3V	750 @ 1.5A, 3V	750 @ 2A, 3V	750 @ 1.5A, 3V
Power - Max	40 W	40 W	40 W	40 W
Operating Temperature (TJ)	150°C	150°C	-55°C ~ 150°C	-55°C ~ 150°C
Mounting Type	Through Hole	Through Hole	Through Hole	Through Hole
Package / Case	TO-225AA, TO-126-3	TO-225AA, TO-126-3	TO-225AA, TO-126-3	TO-225AA, TO-126-3
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
REACH Status	REACH Unaffected	REACH Unaffected	REACH Unaffected	REACH Unaffected

Engineering Selection Recommendations

Primary Substitute: BD680 (STMicroelectronics)

The BD680 is the recommended substitute for the obsolete BD680A. Both parts are manufactured by STMicroelectronics and share identical electrical specifications. The BD680 maintains Active product status, ensuring long-term availability and supply chain continuity. Both parts are ROHS3 Compliant and REACH Unaffected, meeting current regulatory requirements.

Alternative Substitutes: MJE703G and MJE702G (onsemi)

The MJE703G and MJE702G are manufactured by onsemi and provide functional equivalence to the BD680A across all critical electrical parameters. Both parts are rated for 80 V, 4 A, and 40 W with PNP Darlington configuration. The onsemi devices feature extended operating temperature ranges (-55°C to 150°C) compared to the BD680A specification (150°C maximum). Both onsemi parts are classified as Obsolete; however, they remain available in inventory.

Compliance Considerations:

All substitute parts maintain ROHS3 Compliance and REACH Unaffected status, ensuring compatibility with current environmental and regulatory standards. Moisture Sensitivity Level (MSL) ratings are equivalent across all parts, with no additional handling precautions required during assembly.

Package Compatibility:

All substitute parts utilize compatible Through Hole packages (TO-225AA, TO-126-3). Physical dimensions and pin configurations are equivalent, permitting direct PCB layout compatibility without redesign.

Frequently Asked Questions (FAQ)

Q: Can the BD680 directly replace the BD680A in existing designs?

A: Yes. The BD680 is electrically and mechanically equivalent to the BD680A. Both parts share identical maximum ratings for collector current (4 A), collector-emitter breakdown voltage (80 V), and power dissipation (40 W). The BD680 is manufactured by the same supplier (STMicroelectronics) and maintains Active product status, providing superior supply chain availability.

Q: What are the differences between the STMicroelectronics BD680 and the onsemi MJE703G?

A: Both parts meet the core electrical requirements of 80 V, 4 A, and 40 W. The primary differences are manufacturer (STMicroelectronics versus onsemi) and collector cutoff current specification (500µA for BD680 versus 100µA for MJE703G). The MJE703G provides a wider operating temperature range (-55°C to 150°C) compared to the BD680A specification. Both parts are Through Hole mounted and ROHS3 Compliant.

Q: Are the MJE702G and MJE703G interchangeable?

A: Yes, within the context of BD680A substitution. Both onsemi parts meet the electrical requirements of 4 A collector current, 80 V breakdown voltage, and 40 W power rating. The MJE702G specifies Vce saturation of 2.5V at 30mA/1.5A, while the MJE703G specifies 2.8V at 40mA/2A. Both parts are Through Hole mounted with compatible package configurations.

Q: Does package selection affect substitution eligibility?

A: Package selection does not affect electrical substitution eligibility. All substitute parts (BD680, MJE703G, MJE702G) are available in compatible Through Hole packages (TO-225AA, TO-126-3). Physical pin configurations and mounting footprints are equivalent, permitting direct PCB compatibility. Verify specific package availability with your supplier based on procurement requirements.

Q: What is the significance of the Vce saturation differences between substitute parts?

A: Vce saturation differences reflect variations in transistor switching characteristics at specified base and collector current levels. The BD680A and MJE703G specify 2.8V saturation at 40mA base current and 2A collector current, while the BD680 and MJE702G specify 2.5V saturation at 30mA base current and 1.5A collector current. These variations do not preclude substitution; circuit design must account for saturation voltage within the application's operating parameters.

Q: Are all substitute parts RoHS compliant?

A: Yes. The BD680A, BD680, MJE703G, and MJE702G are all ROHS3 Compliant and REACH Unaffected. All parts meet current environmental and regulatory standards for electronic component manufacturing and use.

Q: What inventory considerations should guide part selection?

A: The BD680 (STMicroelectronics) maintains the highest inventory availability at 8200 pieces and Active product status, providing optimal long-term supply security. The MJE702G (onsemi) maintains substantial inventory at 37,790 pieces despite Obsolete classification. The BD680A and MJE703G are classified as Obsolete with lower inventory levels (4100 and 2400 pieces respectively). For new designs or long-term production, the BD680 is the preferred selection.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message