component

BC857A

Public Made by Adom

by adom

Nexperia Bipolar (BJT), SOT-23. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.

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Generated by kicad-footprint-generator · KiCad file format 20260206
Name Last commit message Last updated
docs Publish 0.1.0 · Ray 27d ago
viewers bc857a: viewers · Ray 27d ago
bc857a-etched.glb bc857a: factory component page (tier=lcsc) · Ray 27d ago
bc857a-etched.step bc857a: factory component page (tier=lcsc) · Ray 27d ago
bc857a-hero.glb bc857a: hero GLB from the etched model (keeps the MPN mark) · Ray 27d ago
bc857a-hero.overlay.json Publish 0.1.0 · Ray 27d ago
bc857a.glb Publish 0.1.0 · Ray 27d ago
bc857a.kicad_mod Publish 0.1.0 · Ray 27d ago
bc857a.kicad_sym Publish 0.1.0 · Ray 27d ago
bc857a.lbr Publish 0.1.0 · Ray 27d ago
bc857a.step Publish 0.1.0 · Ray 27d ago
package.json Publish 0.1.0 · Ray 27d ago
page.json bc857a: specified limits as data (metadata.characteristics, 26 rows from the datasheet) · Ray 20d ago
README.md bc857a: specified limits as data (metadata.characteristics, 26 rows from the datasheet) · Ray 20d ago

BC857A

Nexperia · Bipolar (BJT) · SOT-23

BC857A from Nexperia, in a SOT-23. 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 B input Base terminal of the PNP transistor; the datasheet limits the emitter-base voltage to -5 V (VEBO) and the peak base current to -200 mA (IBM).
2 E passive Emitter terminal of the PNP transistor; the emitter-base breakdown voltage is -5 V minimum at IE = -100 µA, and VEBO is limited to -5 V.
3 C passive Collector terminal of the PNP transistor; for BC857A the collector-emitter voltage is limited to -45 V (VCEO) and the collector current to -100 mA (IC), with a peak of -200 mA (ICM).

Key specifications

Parameter Value
Manufacturer Nexperia
Package SOT-23
Category Transistors/Thyristors
Pins 3

Electrical characteristics

Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).

Parameter Symbol Min Typ Max Unit Conditions Page
collector-base voltage (BC857; BC857A; BC857B; BC857C) VCBO -50 V open emitter 3
collector-emitter voltage (BC857; BC857A; BC857B; BC857C) VCEO -45 V open base 3
emitter-base voltage VEBO -5 V open collector 3
collector current IC -100 mA 3
peak collector current ICM -200 mA 3
peak base current IBM -200 mA 3
total power dissipation Ptot 250 mW Tamb ≤ 25 °C [1] 3
junction temperature Tj 150 °C 3
ambient temperature Tamb -65 150 °C 3
storage temperature Tstg -65 150 °C 3
thermal resistance from junction to ambient Rth(j-a) 500 K/W in free air [1] 4
collector-base breakdown voltage (BC857A) V(BR)CBO -50 V IC = -100 µA; IE = 0 A 5
collector-emitter breakdown voltage (BC857A) V(BR)CEO -45 V IC = -2 mA; IB = 0 A 5
emitter-base breakdown voltage V(BR)EBO -5 V IC = 0 A; IE = -100 µA 5
collector-base cut-off current ICBO -1 -15 nA VCB = -30 V; IE = 0 A 5
collector-base cut-off current ICBO -4 µA VCB = -30 V; IE = 0 A; Tj = 150 °C 5
emitter-base cut-off current IEBO -100 nA VEB = -5 V; IC = 0 A 5
DC current gain (BC857A) hFE 125 250 VCE = -5 V; IC = -2 mA 5
collector-emitter saturation voltage VCEsat -75 -300 mV IC = -10 mA; IB = -0.5 mA 5
collector-emitter saturation voltage VCEsat -250 -650 mV IC = -100 mA; IB = -5 mA; pulsed; tp ≤ 300 µs; δ ≤ 0.02 5
base-emitter saturation voltage VBEsat -700 mV IC = -10 mA; IB = -0.5 mA; pulsed; tp ≤ 300 µs; δ ≤ 0.02 5
base-emitter saturation voltage VBEsat -850 mV IC = -100 mA; IB = -5 mA; pulsed; tp ≤ 300 µs; δ ≤ 0.02 5
base-emitter voltage VBE -600 -650 -750 mV VCE = -5 V; IC = -2 mA 5
base-emitter voltage VBE -820 mV VCE = -5 V; IC = -10 mA 5
transition frequency fT 100 MHz VCE = -5 V; IC = -10 mA; f = 100 MHz 5
noise figure NF 2 10 dB IC = -200 µA; VCE = -5 V; RS = 2 kΩ; f = 1 kHz; B = 200 Hz 5

CAD (KiCad official)

  • Symbol: BC857A
  • Footprint: Package_TO_SOT_SMD:SOT-23
  • 3D model: SOT-23 (KiCad packages3D, STEP)
  • 3D model files: bc857a-etched.step / bc857a-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); bc857a.step / bc857a.glb are the bare package body.

Provenance

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

  • Datasheet: Nexperia datasheet (13 pp, sha256 d9a836e40dd8f1e7, 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