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BC857B-QR

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by adom

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

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Made with kicad-footprint-generator 10.0 · KiCad file format 20260206
Name Last commit message Last updated
docs bc857b-qr: re-etch, flat white mark read from pin 1 (service-occt 1.4.0) + chip hero · Ray
viewers bc857b-qr: symbol viewer · Ray
bc857b-qr-etched.fit.json bc857b-qr: re-etch, flat white mark read from pin 1 (service-occt 1.4.0) + chip hero · Ray
bc857b-qr-etched.glb bc857b-qr: one-pass backfill (symbol Device:Q_PNP, re-etched, hero rebuilt in-pass (inputs changed)) · Ray
bc857b-qr-etched.step bc857b-qr: one-pass backfill (symbol Device:Q_PNP, re-etched, hero rebuilt in-pass (inputs changed)) · Ray
bc857b-qr-hero.glb bc857b-qr: hero from the plain model · Ray
bc857b-qr-hero.overlay.json bc857b-qr: hero from the plain model · Ray
bc857b-qr.glb Publish 0.1.0 · Ray
bc857b-qr.kicad_mod Publish 0.1.0 · Ray
bc857b-qr.kicad_sym bc857b-qr: one-pass backfill (symbol Device:Q_PNP, re-etched, hero rebuilt in-pass (inputs changed)) · Ray
bc857b-qr.lbr bc857b-qr: one-pass backfill (symbol Device:Q_PNP, re-etched, hero rebuilt in-pass (inputs changed)) · Ray
bc857b-qr.step Publish 0.1.0 · Ray
package.json Publish 0.1.1 · Ray
page.json Publish 0.1.1 · Ray
README.md bc857b-qr: specified limits as data (metadata.characteristics, 27 rows from the datasheet) · Ray

BC857B-QR

Nexperia · Bipolar (BJT) · SOT-23

BC857B-QR from Nexperia, in a SOT-23. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 B input Base terminal for transistor control; DC current gain (hFE) ranges from 220 to 475 at VCE = −5 V and IC = −2 mA.
2 E passive Emitter terminal; maximum base-emitter voltage (VEBO) is −5 V.
3 C passive Collector terminal; maximum collector-emitter voltage (VCEO) is −45 V and maximum collector current (IC) is −100 mA.

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 VCBO -50 V open emitter 3
collector-emitter voltage 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; device mounted on FR4 PCB [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; device mounted on FR4 PCB, single-sided, 35 µm copper [1] 4
collector-base breakdown voltage V(BR)CBO -50 V IC = -100 µA; IE = 0 A 5
collector-emitter breakdown voltage 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 hFE 220 475 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 [1] 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
base-emitter saturation voltage VBEsat -700 mV IC = -10 mA; IB = -0.5 mA; pulsed; tp ≤ 300 μs; δ ≤ 0.02 [1] 5
base-emitter saturation voltage VBEsat -850 mV IC = -100 mA; IB = -5 mA; pulsed; tp ≤ 300 μs; δ ≤ 0.02 [1] 5
collector capacitance Cc 4.5 pF VCB = -10 V; IE = ie = 0 A; f = 1 MHz 5

CAD (KiCad official)

  • Symbol: BC857B-QR
  • Footprint: Package_TO_SOT_SMD:SOT-23
  • 3D model: SOT-23 (KiCad packages3D, STEP)
  • 3D model files: bc857b-qr-etched.step / bc857b-qr-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); bc857b-qr.step / bc857b-qr.glb are the bare package body.

Provenance

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

  • Datasheet: Nexperia datasheet (13 pp, sha256 51197e747b27e7b9, retrieved 2026-09-23, tier: lcsc)
  • Extractor: parts-factory 2.0.0 / extract_pins 0.2, primary claude-haiku-4-5-20251001 (text), consensus claude-sonnet-4-6 (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