component
BC857B-QR
Public Made by Adomby adom
Nexperia Bipolar (BJT), SOT-23. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
Open in new tab ↗
Loads when you scroll to it. Unloads after 5 minutes in the background.
Symbol & Footprint
Schematic Symbol
Open full view ↗Loads when you scroll to it. Unloads after 5 minutes in the background.
PCB Footprint
Open full view ↗Loads when you scroll to it. Unloads after 5 minutes in the background.
Datasheet
Open in new tab ↗Loads when you scroll to it. Unloads after 5 minutes in the background.
README
markdownBC857B-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.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);bc857b-qr.step/bc857b-qr.glbare 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, primaryclaude-haiku-4-5-20251001(text), consensusclaude-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).