BC847 NPN Transistor Technical Summary

Overview

The BC847 is a general-purpose NPN bipolar junction transistor (BJT) housed in an SC-75 plastic package. Designed for low-power amplification and switching applications, this transistor offers reliable performance in a compact form factor. Its low current and voltage characteristics make it suitable for a wide range of electronic circuits, particularly in consumer electronics, signal processing, and control systems.

The BC847 is part of a family of transistors that includes complementary PNP types, allowing for flexible circuit design. Its small footprint and robust performance make it a popular choice for space-constrained applications.

Features

• Low Current Handling: Maximum collector current (Ic) of 100 mA, making it ideal for low-power applications.
• Low Voltage Operation: Collector-emitter voltage (V_CEO) of up to 65 V, suitable for low-voltage circuits.
• High Current Gain (h_FE): Offers a typical current gain range of 110 to 800, ensuring efficient signal amplification.
• Compact SC-75 Package: Small surface-mount package (also known as SOT-416) for space-efficient PCB designs.
• Low Noise: Excellent noise performance, making it suitable for audio and RF applications.
• Complementary PNP Available: Pairs with the BC857 PNP transistor for push-pull and other complementary configurations.
• RoHS Compliant: Meets environmental standards for lead-free and hazardous substance-free manufacturing.

Applications

The BC847 is versatile and finds use in a variety of electronic circuits, including but not limited to:

• Signal Amplification: Used in small-signal amplifiers for audio and RF applications.
• Switching Circuits: Suitable for low-power switching in digital and analog systems.
• Consumer Electronics: Commonly found in remote controls, LED drivers, and portable devices.
• Sensor Interfaces: Amplifies weak signals from sensors in IoT and industrial applications.
• Oscillators and Timers: Used in oscillator circuits for clock generation and timing applications.
• Audio Preamplifiers: Provides low-noise amplification in microphone and line-level audio circuits.

Electrical Characteristics

The following tables outline the key electrical specifications of the BC847 transistor under typical operating conditions (unless otherwise noted).

Absolute Maximum Ratings

• Collector-Emitter Voltage (V_CEO): 65 V
• Collector-Base Voltage (V_CBO): 80 V
• Emitter-Base Voltage (V_EBO): 6 V
• Collector Current (I_C): 100 mA
• Total Power Dissipation (P_tot): 250 mW at 25°C
• Operating and Storage Temperature Range (T_j, T_stg): -55°C to +150°C

Typical Electrical Characteristics (T_a = 25°C)

• DC Current Gain (h_FE):
  • 110 (min) to 800 (max), depending on variant (A, B, or C grade)
• Collector-Emitter Saturation Voltage (V_CE(sat)):
  • 0.6 V (max) at I_C = 100 mA, I_B = 5 mA
• Base-Emitter Saturation Voltage (V_BE(sat)):
  • 1.2 V (max) at I_C = 100 mA, I_B = 5 mA
• Transition Frequency (f_T):
  • 100 MHz (typical) at V_CE = 5 V, I_C = 10 mA
• Noise Figure (NF):
  • 1 dB (typical) at f = 1 kHz, I_C = 100 µA, V_CE = 5 V

Package Information

The BC847 is available in an SC-75 (SOT-416) surface-mount package, which is designed for high-density PCB layouts. Below are the key mechanical details:

SC-75 (SOT-416) Package Dimensions

• Package Length: 1.6 mm (max)
• Package Width: 1.2 mm (max)
• Package Height: 0.6 mm (max)
• Lead Pitch: 0.65 mm
• Termination: Tin-plated leads for reliable soldering

Marking and Pinout

• Device Marking: "1A" (or similar, depending on manufacturer and variant)
• Pin Configuration (from left to right, viewing from marked side):
  1. Emitter (E)
  2. Base (B)
  3. Collector (C)

Conclusion

The BC847 NPN transistor is a versatile and reliable component for low-power amplification and switching applications. Its compact SC-75 package, combined with robust electrical characteristics, makes it an excellent choice for modern electronics where space and efficiency are critical. Whether used in consumer electronics, industrial controls, or audio circuits, the BC847 delivers consistent performance and ease of integration.