BD137 Equivalent & Substitute Parts

Part Overview

The BD137 is a Bipolar (BJT) Transistor NPN rated for 60 V collector-emitter breakdown voltage and 1.5 A maximum collector current in a Through Hole TO-126 package. This component is classified as Obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement continuity. The BD137 delivers 1.25 W maximum power dissipation with a minimum DC current gain of 40 at 150 mA collector current and 2 V collector-emitter voltage.

Substiute Parts

BD137

onsemiIn Stock: 9628BD137 Datasheet

Current PartRFQ

BD137G

onsemiIn Stock: 3435BD137G Datasheet

DirectRFQ

BD135

STMicroelectronicsIn Stock: 26528BD135 Datasheet

SimilarRFQ

BD139

STMicroelectronicsIn Stock: 435414BD139 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BD137 is determined by electrical and mechanical compatibility across the following critical parameters:

Electrical Compatibility Criteria:

• Transistor Type: NPN configuration
• Maximum Collector Current (Ic): 1.5 A
• Vce Saturation characteristics: 500mV @ 50mA, 500mA
• Current Cutoff (ICBO): 100nA
• DC Current Gain (hFE): Minimum 40 @ 150mA, 2V
• Power Dissipation: 1.25 W

Mechanical Compatibility Criteria:

• Mounting Type: Through Hole
• Package / Case: TO-225AA, TO-126-3 or equivalent SOT-32-3

Voltage Rating Consideration: Substitutes are grouped by collector-emitter breakdown voltage. The BD137 operates at 60 V maximum. Substitutes with equal or higher voltage ratings (BD137G at 60 V, BD139 at 80 V) are direct electrical equivalents. The BD135 operates at 45 V and represents a lower-voltage alternative suitable only for applications with reduced voltage requirements.

Parameter Comparison

Engineering Selection Recommendations

BD137G (Direct Equivalent - Recommended Primary Substitute)

The BD137G is the direct equivalent of the BD137, manufactured by onsemi with identical electrical specifications and package configuration. The BD137G maintains all critical parameters: 60 V collector-emitter breakdown voltage, 1.5 A maximum collector current, 1.25 W power dissipation, and TO-126 package. The BD137G holds Active product status and ROHS3 compliance, providing long-term availability and regulatory alignment. This part is the preferred substitute for direct replacement in existing designs.

BD139 (Higher Voltage Alternative)

The BD139, manufactured by STMicroelectronics, provides equivalent electrical performance with an elevated collector-emitter breakdown voltage of 80 V. All other electrical parameters remain identical to the BD137: 1.5 A collector current, 1.25 W power dissipation, and matching saturation characteristics. The BD139 is suitable for applications requiring higher voltage headroom or operating in higher-voltage environments. The BD139 is Active and ROHS3 compliant. Package configuration is SOT-32-3, which maintains Through Hole mounting compatibility.

BD135 (Lower Voltage Alternative)

The BD135, manufactured by STMicroelectronics, operates at a reduced collector-emitter breakdown voltage of 45 V. All other electrical parameters match the BD137: 1.5 A collector current, 1.25 W power dissipation, and identical saturation characteristics. The BD135 is suitable only for applications with maximum operating voltages at or below 45 V. The BD135 is Active and ROHS3 compliant. Package configuration is SOT-32-3, maintaining Through Hole mounting compatibility.

Frequently Asked Questions (FAQ)

Q: Can BD137G be used as a direct replacement for BD137?

A: Yes. The BD137G is manufactured by onsemi with identical electrical specifications and package configuration. All critical parameters—60 V breakdown voltage, 1.5 A collector current, 1.25 W power dissipation, and TO-126 package—are matched. The BD137G is Active and ROHS3 compliant, providing superior long-term availability compared to the Obsolete BD137.

Q: What is the difference between BD137 and BD139?

A: The primary difference is collector-emitter breakdown voltage. The BD137 is rated for 60 V maximum, while the BD139 is rated for 80 V maximum. All other electrical parameters are identical: 1.5 A collector current, 1.25 W power dissipation, 500mV saturation voltage, and 40 minimum DC current gain. The BD139 is suitable for higher-voltage applications or designs requiring additional voltage margin.

Q: Can BD135 replace BD137 in all applications?

A: No. The BD135 operates at a maximum collector-emitter breakdown voltage of 45 V, compared to the BD137's 60 V rating. The BD135 is suitable only for applications with maximum operating voltages at or below 45 V. All other electrical parameters are identical. Verify circuit voltage requirements before substituting with BD135.

Q: Are there package differences between these substitutes?

A: The BD137 and BD137G use TO-126 package configuration. The BD135 and BD139 use SOT-32-3 package configuration. Both package types are Through Hole mounting and compatible with standard PCB layouts designed for TO-126 or SOT-32-3 footprints. Verify PCB footprint compatibility before component selection.

Q: What is the RoHS compliance status of these parts?

A: The BD137 is RoHS non-compliant. The BD137G, BD135, and BD139 are all ROHS3 compliant. For applications requiring RoHS compliance, select BD137G, BD135, or BD139.

Q: What is the operating temperature range for each part?

A: The BD137 and BD137G operate from -55°C to 150°C junction temperature. The BD135 and BD139 operate at a maximum junction temperature of 150°C without specified minimum temperature. Verify temperature requirements for your application.

Q: Which substitute has the highest inventory availability?

A: The BD139 has the highest inventory availability at 435,400 pieces in stock, followed by BD135 at 26,500 pieces, BD137G at 3,400 pieces, and BD137 at 9,523 pieces.