2N3055 Equivalent & Substitute Parts

Part Overview

The 2N3055 is an NPN bipolar junction transistor (BJT) manufactured by STMicroelectronics, rated for 60 V collector-emitter breakdown voltage and 15 A maximum collector current with 115 W power dissipation capability. The device is housed in a TO-3 (TO-204AA) chassis mount package and is classified as obsolete. Due to its obsolete status, equivalent and substitute parts from active manufacturers are necessary for new designs and ongoing production requirements. Substitute devices must maintain electrical compatibility within the specified parameter ranges while accommodating modern packaging and manufacturing standards.

Key Parameters

Parameter	Value	Unit
Transistor Type	NPN	—
Voltage - Collector Emitter Breakdown (Max)	60	V
Current - Collector (Ic) (Max)	15	A
Power - Max	115	W
Vce Saturation (Max) @ Ib, Ic	3V @ 3.3A, 10A	—
Current - Collector Cutoff (Max)	700	µA
DC Current Gain (hFE) (Min) @ Ic, Vce	20 @ 4A, 4V	—
Operating Temperature (TJ)	200	°C
Package / Case	TO-204AA, TO-3	—
Mounting Type	Chassis Mount	—

Substitute Part Grouping Explanation

Substitute parts for the 2N3055 are classified into two categories based on electrical parameter compatibility:

Direct Electrical Equivalents maintain all critical electrical specifications: 60 V collector-emitter breakdown voltage, 15 A maximum collector current, 115 W power dissipation, 3 V Vce saturation at specified bias conditions, 700 µA collector cutoff current, and 20 minimum DC current gain at 4 A and 4 V. These parts are functionally interchangeable in applications designed for the 2N3055.

Similar Electrical Characteristics share the same transistor type (NPN), package family (TO-3/TO-204AA), and mounting configuration but differ in one or more critical electrical parameters such as voltage rating, current rating, power dissipation, or saturation characteristics. These parts are suitable for applications where the specific parameter deviation does not compromise circuit performance.

The key parameters determining substitution eligibility are: transistor type (NPN), collector-emitter breakdown voltage (60 V minimum), collector current capability (15 A minimum), power dissipation (115 W minimum), and package compatibility (TO-3/TO-204AA).

Parameter Comparison

Part Number	Manufacturer	Product Status	Transistor Type	Vce Breakdown (V)	Ic Max (A)	Power Max (W)	Vce Sat @ Ib, Ic	Ic Cutoff (µA)	hFE Min @ Ic, Vce	Package	Mounting
2N3055	STMicroelectronics	Obsolete	NPN	60	15	115	3V @ 3.3A, 10A	700	20 @ 4A, 4V	TO-204AA, TO-3	Chassis Mount
2N3055G	onsemi	Active	NPN	60	15	115	3V @ 3.3A, 10A	700	20 @ 4A, 4V	TO-204AA, TO-3	Through Hole
2N3055AG	onsemi	Active	NPN	60	15	115	5V @ 7A, 15A	700	10 @ 4A, 2V	TO-204AA, TO-3	Through Hole
2N3055	Microchip Technology	Active	NPN	70	15	6	2V @ 3.3A, 10A	1000	20 @ 4A, 4V	TO-204AA, TO-3	Through Hole
2N3445	Microchip Technology	Active	NPN	60	7	115	1.5V @ 300µA, 3mA	—	—	TO-204AA, TO-3	Through Hole
2N3446	Microchip Technology	Active	NPN	80	7.5	115	—	—	TO-204AA, TO-3	Through Hole
2N3442	Microchip Technology	Active	NPN	140	10	6	1V @ 300mA, 3A	1000	20 @ 3A, 4V	TO-204AA, TO-3	Through Hole
2N3715	Microchip Technology	Active	NPN	60	0.001	5	2.5V @ 2A, 10A	1000	50 @ 1A, 2V	TO-204AA, TO-3	Through Hole

Engineering Selection Recommendations

Direct Equivalent Selection:

The 2N3055G manufactured by onsemi is the primary direct equivalent for the obsolete STMicroelectronics 2N3055. This device maintains identical electrical specifications across all critical parameters: 60 V breakdown voltage, 15 A collector current, 115 W power dissipation, and matching saturation and gain characteristics. The 2N3055G is classified as active product status and carries ROHS3 compliance certification. The primary difference is mounting configuration (Through Hole versus Chassis Mount), which is accommodated through standard PCB design practices. This part is suitable for direct substitution in new designs and production replacements.

Alternative Equivalent Selection:

The 2N3055AG from onsemi provides electrical equivalence with modified saturation characteristics (5V @ 7A, 15A versus 3V @ 3.3A, 10A) and reduced DC current gain (10 @ 4A, 2V versus 20 @ 4A, 4V). This device maintains the 60 V voltage rating, 15 A current capability, and 115 W power dissipation. The 2N3055AG is active product status with ROHS3 compliance. Selection of this part requires circuit analysis to confirm that the higher saturation voltage and lower gain do not degrade circuit performance.

Partial Specification Alternatives:

The Microchip Technology 2N3055 variant maintains the 15 A collector current and TO-3 package but features 70 V breakdown voltage (exceeding the 60 V specification) and reduced power dissipation (6 W versus 115 W). This part is suitable only for applications where power dissipation requirements are significantly lower than the original design specification.

The 2N3445 and 2N3446 devices provide 115 W power dissipation and TO-3 packaging but with reduced collector current ratings (7 A and 7.5 A respectively). These parts are applicable only in current-limited applications where the 15 A capability is not required.

The 2N3442 provides higher voltage capability (140 V) but reduced current (10 A) and power (6 W), making it unsuitable for applications requiring the full 15 A and 115 W specifications.

All recommended substitutes carry ROHS3 compliance and REACH Unaffected status, meeting modern regulatory requirements.

Frequently Asked Questions (FAQ)

Q: Can the 2N3055G directly replace the STMicroelectronics 2N3055 in existing designs?

A: Yes. The 2N3055G from onsemi maintains identical electrical specifications for all critical parameters: 60 V breakdown voltage, 15 A maximum collector current, 115 W power dissipation, and matching saturation and gain characteristics. The mounting configuration difference (Through Hole versus Chassis Mount) is accommodated through standard PCB design practices. No circuit modifications are required.

Q: What is the difference between the 2N3055G and 2N3055AG?

A: Both devices are manufactured by onsemi and maintain 60 V breakdown voltage, 15 A collector current, and 115 W power dissipation. The 2N3055AG exhibits higher saturation voltage (5V @ 7A, 15A versus 3V @ 3.3A, 10A) and lower DC current gain (10 @ 4A, 2V versus 20 @ 4A, 4V). The 2N3055G is the preferred direct equivalent. The 2N3055AG is suitable only when circuit analysis confirms that the modified saturation and gain characteristics do not compromise performance.

Q: Why is the Microchip Technology 2N3055 not a suitable substitute despite sharing the same part number?

A: Although both devices share the 2N3055 designation and TO-3 package, the Microchip variant specifies 70 V breakdown voltage and only 6 W power dissipation compared to the original 60 V and 115 W. The reduced power rating makes this device unsuitable for applications requiring the full 115 W dissipation capability. The higher voltage rating does not compensate for the power limitation.

Q: Can the 2N3445 or 2N3446 be used as substitutes?

A: The 2N3445 and 2N3446 are suitable only for applications where collector current requirements do not exceed 7 A and 7.5 A respectively. Both devices maintain 115 W power dissipation and 60 V or 80 V breakdown voltage. These parts are not suitable for applications requiring the full 15 A collector current capability of the original 2N3055.

Q: What compliance certifications apply to substitute parts?

A: All recommended substitute parts carry ROHS3 compliance certification and REACH Unaffected status, meeting current regulatory requirements for electronic components. The original STMicroelectronics 2N3055 also carries these certifications, ensuring regulatory continuity in design transitions.

Q: Are there packaging considerations when substituting the 2N3055?

A: The original 2N3055 is specified as Chassis Mount in TO-3 package. Direct equivalents such as the 2N3055G are specified as Through Hole in TO-204 (TO-3) package. Both configurations use the same TO-3 physical form factor and are compatible with standard TO-3 mounting hardware and thermal management solutions. PCB design practices accommodate the mounting configuration difference without requiring circuit modifications.

Q: What is the inventory status of substitute parts?

A: The 2N3055G from onsemi has 1451 pieces in stock. The 2N3055AG from onsemi has 1412 pieces in stock. The Microchip Technology 2N3055 variant has 1845 pieces in stock. All substitute parts are available as new original components.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message