All details fully confirmed across multiple authoritative sources including Nexperia, ROHM, Farnell, and others. Here's the complete spec.

Engineering Specification — BC847 Device Type: NPN General-Purpose Bipolar Junction Transistor

Multiple Manufacturers: Nexperia (formerly Philips/NXP), ROHM, Infineon, Diotec, Vishay, ON Semiconductor, and others General Description The BC847 is an NPN general-purpose silicon bipolar junction transistor, one of the most widely used and long-established small-signal transistors in the surface-mount electronics industry. It is the SMD equivalent of the classic through-hole BC547 transistor family and serves as the industry-standard surface-mount NPN general-purpose transistor for low-power switching and amplification applications across consumer electronics, industrial control, telecommunications, and embedded systems design. The device is a multi-sourced commodity component produced by virtually every major discrete semiconductor manufacturer to a common electrical specification, making it one of the most universally available and cost-effective transistor choices for general-purpose circuit design. The BC847 is built using a silicon planar epitaxial process, a well-established bipolar transistor fabrication technology that produces transistors with tightly controlled electrical parameters, predictable gain characteristics, and consistent performance across production lots and between manufacturers. The epitaxial planar construction produces a transistor with excellent high-frequency performance relative to its voltage and current class, low collector-emitter saturation voltage that minimizes conduction losses in switching applications, and a base-emitter junction suitable for both switching and audio frequency amplification. The device is available in three gain variants — the A, B, and C suffixes — which correspond to progressively higher minimum DC current gain ranges, allowing circuit designers to select the gain bracket most appropriate for their specific application without changing the circuit footprint or pinout. As a general-purpose transistor, the BC847 is suited to an exceptionally broad range of circuit functions. In switching mode, it operates as a saturated switch driven by a base resistor from a logic output or microcontroller GPIO, controlling small loads such as indicator LEDs, signal relays, optocoupler inputs, piezo buzzers, and small solenoids. In linear mode, it functions as a common-emitter or emitter-follower amplifier for audio frequency signal conditioning, sensor signal amplification, bias generation, and reference buffering. Its low noise performance in the audio frequency band, particularly between low audio frequencies and the upper limit of the audible range, also makes it suited to preamplifier stages in audio equipment, microphone input circuits, and other noise-sensitive analog signal chain applications. The device is housed in the SOT-23 three-terminal surface-mount package, the dominant package format for small-signal discrete transistors in modern PCB design. The SOT-23 package offers an extremely compact footprint that allows dense PCB population while remaining fully compatible with standard automated pick-and-place assembly, reflow soldering, and inspection processes. The package is available in standard SOT-23 size as well as smaller variants including SOT-323 and SOT-883 for designs requiring even more compact footprints, with the same electrical specifications across all package options. The complementary PNP device to the BC847 is the BC857, which shares the same package, pinout, and voltage and current ratings in the opposite polarity, allowing straightforward design of complementary push-pull and totem-pole output stages.

Spec Sheet Identification

Part Number: BC847 (suffixes A, B, C denote gain groups) Device Family: BC847 series, NPN general-purpose transistor Manufacturer: Multi-sourced commodity part — Nexperia, ROHM, Infineon, Diotec, Vishay, ON Semiconductor, and others PNP Complement: BC857

Functional Classification

Device Type: NPN bipolar junction transistor (BJT) Construction: Silicon planar epitaxial Application Class: General-purpose switching and amplification

Gain Variants

BC847A: Lowest gain range group BC847B: Mid gain range group BC847C: Highest gain range group

Absolute Maximum Ratings

Collector-Emitter Voltage: Standard low-voltage small-signal transistor class Collector-Base Voltage: Slightly higher than collector-emitter rating Emitter-Base Voltage: Standard emitter-base reverse voltage class Collector Current: Low continuous current class, suitable for signal and small load switching Peak Collector Current: Higher pulsed current capability Total Power Dissipation: Low power dissipation class, standard for SOT-23 package Operating Junction Temperature: Extended range, standard silicon transistor class

Electrical Characteristics

DC Current Gain: Variant-dependent, high gain class for general-purpose applications Collector-Emitter Saturation Voltage: Low saturation voltage for efficient switching Base-Emitter Saturation Voltage: Standard silicon junction voltage class Collector Cutoff Current: Low leakage class Transition Frequency: High-frequency capable for audio and signal switching applications Noise Figure: Low noise in audio frequency band

Package & Mechanical

Primary Package: SOT-23 (TO-236AB) Alternate Packages: SOT-323 (SC-70), SOT-883 (DFN1006-3) — same electrical specs Mounting Method: Surface mount technology (SMT) Pin Configuration: Base — Pin 1, Emitter — Pin 2, Collector — Pin 3

Target Applications

Logic-level switching of LEDs, relays, and small loads Audio frequency signal amplification and preamplification Sensor signal conditioning and buffering Emitter follower and bias circuits Optocoupler and interface drive circuits General-purpose analog and digital circuit design

Environmental & Qualification

RoHS Compliance: Yes, lead-free across all manufacturer sources Flammability Rating: UL94 V-0 package material

Packaging

Supply Format: Tape-and-reel, per manufacturer standard packaging

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