BD239B-S Equivalent & Substitute Parts

Part Overview

The BD239B-S is an NPN bipolar junction transistor manufactured by Bourns Inc., rated for 80 V collector-emitter breakdown voltage and 2 A maximum collector current in a TO-220 through-hole package. This device is classified as obsolete, necessitating identification of active equivalent and substitute components for ongoing design requirements and production continuity. The part operates across a temperature range of -65°C to 150°C and is RoHS3 compliant with MSL 1 rating.

Substiute Parts

BD239B-S

Bourns Inc.In Stock: 1236BD239B-S Datasheet

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2N6488G

onsemiIn Stock: 73072N6488G Datasheet

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D44H11

Solid State Inc.In Stock: 25298D44H11 Datasheet

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TIP29BG

onsemiIn Stock: 4477TIP29BG Datasheet

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TIP31BG

onsemiIn Stock: 2013TIP31BG Datasheet

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TIP41BG

onsemiIn Stock: 20347TIP41BG Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the BD239B-S is determined by the following critical parameters: NPN transistor type, 80 V collector-emitter breakdown voltage rating, TO-220-3 package configuration, through-hole mounting, and operating temperature range of -65°C to 150°C. All substitute parts listed maintain these core electrical and mechanical specifications.

Substitute parts are grouped by maximum collector current rating, which represents the primary differentiator among available alternatives:

Direct Current Rating Match (1-2 A): TIP29BG provides equivalent 1 A maximum collector current with matching saturation voltage and current gain characteristics.

Higher Current Capacity (3-6 A): TIP31BG (3 A) and TIP41BG (6 A) offer increased current handling while maintaining the 80 V voltage rating and TO-220 package.

Significantly Higher Current Capacity (15 A): 2N6488G provides substantially elevated current capability for applications requiring higher current throughput.

Incomplete Specification Data: D44H11 is listed as an NPN TO-220 device but lacks sufficient electrical parameter documentation for detailed comparison.

Parameter Comparison

Engineering Selection Recommendations

TIP29BG is the closest functional equivalent to BD239B-S, offering identical maximum collector current (1 A), saturation voltage characteristics, current gain specifications, and power rating. This part is manufactured by onsemi, carries active product status, and maintains full RoHS3 compliance with REACH unaffected designation. TIP29BG is suitable for direct replacement in applications operating at or below 1 A collector current.

TIP31BG provides a mid-range alternative with 3 A maximum collector current capacity while maintaining the 80 V voltage rating and TO-220 package. This part is active and RoHS3 compliant, appropriate for designs requiring current headroom above the original 2 A specification.

TIP41BG extends current capability to 6 A with the same voltage and package specifications. This active, RoHS3-compliant device accommodates higher current applications while preserving thermal and electrical compatibility within the TO-220 form factor.

2N6488G offers substantially higher current capacity at 15 A, manufactured by onsemi with active status and RoHS3 compliance. This part is suitable only for applications where significantly elevated current handling is required, as the increased collector cutoff current (1mA versus 300µA) and higher saturation voltage may affect circuit performance in low-current or precision applications.

D44H11 is listed as an active NPN TO-220 device; however, insufficient electrical parameter data prevents detailed compatibility assessment. This part should be evaluated only when complete specification documentation is available.

Frequently Asked Questions (FAQ)

Q: Can TIP29BG directly replace BD239B-S in all applications?

A: TIP29BG is a direct functional equivalent for applications operating at or below 1 A collector current. Both devices share identical maximum collector current (1 A), saturation voltage (700mV @ 200mA, 1A), DC current gain (15 @ 1A, 4V), and power rating (2 W). The 80 V voltage rating and TO-220-3 package are identical. TIP29BG is active and RoHS3 compliant, making it suitable for direct substitution in existing designs.

Q: What is the difference between TIP29BG, TIP31BG, and TIP41BG?

A: These three parts differ primarily in maximum collector current rating: TIP29BG (1 A), TIP31BG (3 A), and TIP41BG (6 A). All three maintain the 80 V collector-emitter breakdown voltage, TO-220-3 package, and -65°C to 150°C operating temperature range. Selection depends on the required current capacity of the application. Higher-rated devices provide current margin but may exhibit different saturation voltage and cutoff current characteristics.

Q: Is 2N6488G suitable as a substitute for BD239B-S?

A: 2N6488G is electrically compatible in terms of voltage rating (80 V) and package (TO-220-3), but differs significantly in current capacity (15 A versus 2 A) and saturation characteristics (3.5V @ 5A, 15A versus 700mV @ 200mA, 1A). This part is appropriate only for applications requiring substantially higher current handling. The elevated saturation voltage and collector cutoff current may alter circuit behavior in designs optimized for the original 2 A specification.

Q: Are all substitute parts RoHS3 compliant?

A: Yes, all listed substitute parts (TIP29BG, TIP31BG, TIP41BG, 2N6488G, and D44H11) are RoHS3 compliant. The original BD239B-S is also RoHS3 compliant. This ensures regulatory compliance across all alternatives.

Q: What is the significance of the TO-220-3 package for substitution?

A: The TO-220-3 package is a standardized through-hole configuration with three leads (Base, Collector, Emitter). All substitute parts maintain this identical package, ensuring mechanical and thermal compatibility with existing PCB layouts, heatsinks, and mounting hardware. No physical modifications to the circuit board or thermal management system are required when substituting between these parts.

Q: Why is D44H11 listed if electrical parameters are incomplete?

A: D44H11 is included in the substitute list based on the provided input data, which identifies it as an NPN transistor in TO-220-3 package with active product status and RoHS3 compliance. However, the absence of detailed electrical specifications (voltage rating, current rating, saturation voltage, current gain) prevents comprehensive compatibility verification. Complete datasheet documentation should be obtained before selecting this part for critical applications.

Q: What operating temperature range do all substitute parts support?

A: All substitute parts (TIP29BG, TIP31BG, TIP41BG, and 2N6488G) operate across the identical temperature range of -65°C to 150°C (junction temperature), matching the original BD239B-S specification. This ensures thermal compatibility across the full operating envelope.

Q: How does collector cutoff current affect substitution decisions?

A: Collector cutoff current (Icbo) represents leakage current when the transistor is in the off state. BD239B-S specifies 300µA maximum. TIP29BG and TIP31BG maintain this specification, while TIP41BG increases to 700µA and 2N6488G to 1mA. Higher cutoff currents may introduce additional leakage in precision analog circuits or low-power applications. For digital switching or high-current applications, this parameter is typically non-critical.