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BD137 NPN Power Transistor

Public Made by Adom

by adom

NPN medium-power transistor, 60 V / 1.5 A, in TO-126 for audio and driver stages.

transistorbjtnpnmedium-powerto-126st
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3D Model

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Symbol & Footprint

Schematic Symbol

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Datasheet

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Contents

README

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BD137

STMicroelectronics · Bipolar Transistor (BJT) · TO-126

The BD137 is an NPN medium-power transistor rated for 60 V and 1.5 A continuous collector current in a TO-126 package. It sits between the BD135 (45 V) and BD139 (80 V) in the series, and is used in audio driver and output stages, discrete regulators, and medium-power switching.

Pinout

Pin Name Type Function
1 E passive Emitter. Typically the low-side reference of the transistor; VCE(sat) ≤ 0.5 V at IC = 0.5 A, IB = 50 mA.
2 C passive Collector. Also thermally/electrically tied to the metal mounting tab of the SOT-32 (TO-126) package. Rated IC = 1.5 A continuous, ICM = 3 A peak; VCEO ≈ 60 V for BD137.
3 B input Base. Controls collector current via base drive; VBE ≈ 1 V at IC = 0.5 A. Absolute max IB = 0.5 A, VEBO = 5 V.

Key specifications

Parameter Value
Type NPN medium-power transistor
Collector-emitter voltage (VCEO) 60 V
Collector current (IC) 1.5 A continuous (3 A peak)
DC current gain (hFE) 40 to 250
Transition frequency (fT) 190 MHz
Power dissipation 12.5 W
Operating temperature -55 C to 150 C

Ordering variants

  • BD137
  • BD137-10
  • BD137-16

CAD (KiCad official)

  • Symbol: bd137.kicad_sym
  • Footprint: bd137.kicad_mod
  • 3D model: TO-126 body from KiCad Package_TO_SOT_THT/TO-126-3_Vertical.
  • 3D model files: bd137-etched.step / bd137-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); bd137.step / bd137.glb are the bare package body.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

  • Datasheet: STMicroelectronics datasheet (9 pp, sha256 9a72cdfa334700b8, retrieved 2026-08-17, tier: manufacturer)
  • Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF