Loads on click. Unloads only if this page sits in the background.

Symbol & Footprint

Schematic Symbol

Open full view ↗
Loads on click. Unloads only if this page sits in the background.

PCB Footprint

Open full view ↗
Loads on click. Unloads only if this page sits in the background.
Loads on click. Unloads only if this page sits in the background.
Download PDF
Contents

README

markdown

2N3055

STMicroelectronics · Bipolar Transistor (BJT) · TO-3

The 2N3055 is a classic NPN power transistor rated for 60 V and 15 A continuous collector current in a metal TO-3 package. It has been a standard pass transistor in linear power supplies and an output device in audio amplifiers for decades. The TO-3 case is the collector, with base and emitter on the two pins.

Pinout

Pin Name Type Function
1 B input Base of NPN power transistor. Drives collector current via hFE (typ. 20-70 at IC = 4 A, VCE = 4 V). VBE ≈ 1.8 V at IC = 4 A. Absolute max IB = 7 A, VEBO = 7 V.
2 E passive Emitter of NPN power transistor. Common return for base-drive and collector current. For NPN 2N3055 normally tied to circuit ground / lower-voltage rail.
3 C passive Collector of NPN power transistor, electrically connected to the TO-3 metal case/mounting tab for heat-sinking. Rated VCBO = 100 V, VCEO = 60 V, IC = 15 A. Must be isolated from grounded heatsinks with a mica/insulator pad.

Key specifications

Parameter Value
Type NPN power transistor
Collector-emitter voltage (VCEO) 60 V
Collector current (IC) 15 A continuous
DC current gain (hFE) 20 to 70 at 4 A
Transition frequency (fT) 2.5 MHz
Power dissipation 115 W
Package TO-3 (case = collector)
Operating temperature -65 C to 200 C

Ordering variants

  • 2N3055

CAD (KiCad official)

  • Symbol: 2n3055.kicad_sym
  • Footprint: 2n3055.kicad_mod
  • 3D model: Metal TO-3 body from KiCad Package_TO_SOT_THT/TO-3.
  • 3D model files: 2n3055-etched.step / 2n3055-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); 2n3055.step / 2n3055.glb are the bare package body.

Provenance

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

  • Datasheet: STMicroelectronics datasheet (7 pp, sha256 c957a8b217de71e5, 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