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Contents

README

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MMBT5551W

CBI · Bipolar (BJT) · SOT-323

MMBT5551W from CBI, in a SOT-323. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 BASE passive Base terminal of the NPN transistor; the datasheet lists it as pin 1 of the SOT-323 package and gives no pin-specific limit, so the device ratings apply (VEBO 6 V, IC 600 mA maximum).
2 EMITTER passive Emitter terminal of the NPN transistor; the datasheet lists it as pin 2 of the SOT-323 package and gives no pin-specific limit, so the device ratings apply (VEBO 6 V, IC 600 mA maximum).
3 COLLECTOR passive Collector terminal of the NPN transistor; the datasheet lists it as pin 3 of the SOT-323 package and gives no pin-specific limit, so the device ratings apply (VCBO 180 V, VCEO 160 V, IC 600 mA maximum).

Key specifications

Parameter Value
Manufacturer CBI
Package SOT-323
Category Transistors/Thyristors
Pins 3

CAD (KiCad official)

  • Symbol: MMBT5551W
  • Footprint: Package_TO_SOT_SMD:SOT-323_SC-70
  • 3D model: SOT-323 (KiCad packages3D, STEP)
  • 3D model files: mmbt5551w-etched.step / mmbt5551w-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); mmbt5551w.step / mmbt5551w.glb are the bare package body.

Provenance

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

  • Datasheet: CBI datasheet (2 pp, sha256 ebc846392ebbd555, retrieved 2026-10-09, tier: lcsc)
  • Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-haiku-5-5 (text), consensus claude-sonnet-5-5 (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF