BD239ATU NPN Bipolar Transistor Equivalent & Substitute Parts

Part Overview

The BD239ATU is an NPN bipolar junction transistor manufactured by onsemi, rated for 60 V collector-emitter breakdown voltage and 2 A maximum collector current in a TO-220-3 through-hole package. This device is classified as obsolete, necessitating identification of functionally equivalent alternatives for ongoing design support and procurement continuity. The BD239ATU delivers 30 W maximum power dissipation with a minimum DC current gain of 15 at 1 A collector current and 4 V collector-emitter voltage.

Key Parameters

Parameter	Value	Unit
Transistor Type	NPN	—
Voltage - Collector Emitter Breakdown (Max)	60	V
Current - Collector (Ic) (Max)	2	A
Power - Max	30	W
Vce Saturation (Max) @ Ib, Ic	700mV @ 200mA, 1A	—
DC Current Gain (hFE) (Min) @ Ic, Vce	15 @ 1A, 4V	—
Current - Collector Cutoff (Max)	300	µA
Operating Temperature (TJ)	150	°C
Package / Case	TO-220-3	—
Mounting Type	Through Hole	—

Substitute Part Grouping Explanation

Substitution of the BD239ATU is determined by alignment of the following critical electrical and mechanical parameters:

Primary Substitution Criteria:

Transistor type: NPN polarity
Package / Case: TO-220-3 through-hole configuration
Voltage - Collector Emitter Breakdown (Max): Equal to or greater than 60 V
Current - Collector (Ic) (Max): Equal to or greater than 2 A
Power - Max: Equal to or greater than 30 W
DC Current Gain (hFE) (Min): Equal to or greater than 15 @ 1A, 4V

Direct Substitutes maintain all electrical specifications at or above the BD239ATU baseline. Similar Substitutes share the same package and polarity but may have different current or power ratings, requiring circuit-level verification for specific applications.

Parameter Comparison

Parameter	BD239ATU	BD239CTU	TIP29AG	TIP29A	TIP31A
Transistor Type	NPN	NPN	NPN	NPN	NPN
Voltage - Collector Emitter Breakdown (Max)	60 V	100 V	60 V	—	60 V
Current - Collector (Ic) (Max)	2 A	2 A	1 A	—	3 A
Power - Max	30 W	30 W	2 W	—	40 W
Vce Saturation (Max) @ Ib, Ic	700mV @ 200mA, 1A	700mV @ 200mA, 1A	700mV @ 125mA, 1A	—	1.2V @ 375mA, 3A
DC Current Gain (hFE) (Min) @ Ic, Vce	15 @ 1A, 4V	15 @ 1A, 4V	15 @ 1A, 4V	—	25 @ 1A, 4V
Current - Collector Cutoff (Max)	300 µA	300 µA	300 µA	—	300 µA
Package / Case	TO-220-3	TO-220-3	TO-220-3	TO-220-3	TO-220-3
Mounting Type	Through Hole	Through Hole	Through Hole	Through Hole	Through Hole
Operating Temperature (TJ)	150°C	150°C	-65°C ~ 150°C	—	-65°C ~ 150°C
Product Status	Obsolete	Last Time Buy	Active	Active	Active

Engineering Selection Recommendations

BD239CTU is the direct manufacturer equivalent from onsemi. It maintains identical electrical specifications (2 A, 30 W, 700 mV saturation) while offering enhanced voltage rating (100 V versus 60 V). The BD239CTU is classified as Last Time Buy, indicating limited future availability. This part is ROHS3 compliant and REACH unaffected, suitable for applications requiring regulatory compliance.

TIP29AG is an active-status alternative from onsemi with identical voltage and saturation characteristics. However, it is rated for 1 A maximum collector current and 2 W power dissipation, making it unsuitable for applications requiring the full 2 A / 30 W capability of the BD239ATU. TIP29AG is ROHS3 compliant with extended operating temperature range (-65°C to 150°C).

TIP29A is an active-status alternative from Solid State Inc. in TO-220-3 package. Insufficient electrical parameter data is provided for complete substitution verification. This part is ROHS3 compliant.

TIP31A is an active-status alternative from Solid State Inc. rated for 3 A collector current and 40 W power dissipation, exceeding BD239ATU specifications. Vce saturation is higher (1.2 V versus 700 mV) and DC current gain is higher (25 versus 15). TIP31A is ROHS3 compliant with extended operating temperature range (-65°C to 150°C). This part is suitable for applications where higher current capacity and power handling are acceptable.

For procurement of obsolete BD239ATU inventory, BD239CTU offers the most direct electrical equivalence with enhanced voltage margin. For new designs, TIP31A provides superior performance headroom with active product status and full regulatory compliance.

Frequently Asked Questions (FAQ)

Q: Can BD239CTU directly replace BD239ATU in existing circuits?

A: Yes. BD239CTU maintains identical maximum collector current (2 A), power dissipation (30 W), saturation voltage (700 mV @ 200mA, 1A), and DC current gain (15 @ 1A, 4V). The higher voltage rating (100 V versus 60 V) provides additional design margin without affecting circuit operation at 60 V or below.

Q: Why is TIP29AG not a suitable replacement for all BD239ATU applications?

A: TIP29AG is rated for 1 A maximum collector current and 2 W power dissipation, compared to BD239ATU specifications of 2 A and 30 W. Applications requiring the full 2 A current capacity or 30 W power handling will exceed TIP29AG ratings. TIP29AG is suitable only for circuits designed for 1 A operation.

Q: What are the key differences between TIP31A and BD239ATU?

A: TIP31A exceeds BD239ATU in collector current (3 A versus 2 A) and power dissipation (40 W versus 30 W). Vce saturation is higher at 1.2 V compared to 700 mV, and DC current gain is higher at 25 versus 15. These differences require circuit-level evaluation to confirm compatibility. TIP31A is suitable for applications where higher current and power capacity are beneficial.

Q: Are all substitute parts available in the same TO-220-3 package?

A: Yes. All listed substitutes (BD239CTU, TIP29AG, TIP29A, TIP31A) are packaged in TO-220-3 through-hole configuration, ensuring mechanical and thermal interface compatibility with existing PCB layouts and heat sinking arrangements.

Q: What is the regulatory compliance status of substitute parts?

A: BD239CTU is ROHS3 compliant and REACH unaffected. TIP29AG, TIP29A, and TIP31A are ROHS3 compliant. All parts are classified under ECCN EAR99. Verify specific regulatory requirements for your application and region.

Q: Is TIP29A a complete substitute for BD239ATU?

A: TIP29A lacks sufficient published electrical parameter data (voltage rating, current rating, power dissipation, saturation voltage, and DC current gain are not specified). Substitution cannot be verified without complete parameter documentation. Contact the manufacturer for detailed specifications before selection.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message