Infineon BC817UE6327 General-Purpose NPN Transistor: Datasheet, Pinout, and Application Circuits

The Infineon BC817UE6327 is a versatile and widely used NPN bipolar junction transistor (BJT) housed in a compact SOT-23 surface-mount package. As a fundamental building block in modern electronics, it is designed for general-purpose amplification and switching applications. Its combination of performance, size, and reliability makes it a popular choice for designers across consumer, industrial, and automotive electronics.

This article provides a detailed overview of its datasheet specifications, pinout configuration, and common circuit implementations.

Datasheet Overview and Key Specifications

The BC817UE6327 is part of a family of transistors, with the "U" suffix denoting its specific DC current gain (hFE) classification. Understanding its absolute maximum ratings and electrical characteristics is crucial for reliable circuit design.

Absolute Maximum Ratings:

Collector-Base Voltage (VCBO): 50 V

Collector-Emitter Voltage (VCEO): 45 V

Emitter-Base Voltage (VEBO): 5 V

Continuous Collector Current (IC): 500 mA

Total Power Dissipation (Ptot): 330 mW (at Tamb = 25°C)

Key Electrical Characteristics (Typ. at IC = 2 mA, VCE = 5 V):

DC Current Gain (hFE): Ranges from 160 to 460 (Group U)

Collector-Emitter Saturation Voltage (VCE(sat)): 0.7 V (max at IC=500 mA, IB=50 mA)

Transition Frequency (fT): 100 MHz

These ratings highlight the transistor's capability to handle moderate current loads and operate effectively at high frequencies, making it suitable for both analog amplification and fast switching tasks.

Pinout Configuration

The BC817UE6327 is packaged in a SOT-23 package, which is a small plastic, surface-mounted device with three pins. When viewing the component with the flat side facing you and the pins pointing downward, the pin assignment is as follows:

Pin 1 (Emitter - E): This is typically connected to ground or the common reference point in a circuit.

Pin 2 (Base - B): This is the control pin. A small current applied to the base controls a larger current flowing between the collector and emitter.

Pin 3 (Collector - C): This is the output pin, usually connected to the load being driven.

Always consult the manufacturer's datasheet for your specific supplier to confirm the pinout, as it can vary between different package styles and manufacturers.

Application Circuits

The BC817UE6327 is most commonly employed in two primary roles: as a switch and as an amplifier.

1. Low-Side Switch Circuit

This is one of the most frequent applications, where the transistor is used to turn a load (like an LED, relay, or motor) on and off using a signal from a microcontroller (e.g., an Arduino or ESP32) or other logic circuit.

Operation: A small current from the microcontroller's GPIO pin (typically 3.3V or 5V) is fed into the base resistor (Rbase). This current allows a much larger current to flow from the collector (connected to the power supply, Vload) through the load and to ground via the emitter. The base resistor is critical for limiting the base current to a safe value for both the microcontroller and the transistor. A formula such as `Rbase ≈ (VGPIO - VBE) / (IC / hFE)` is used to calculate its value.

2. Common-Emitter Amplifier

In this configuration, the transistor is used to amplify a small AC signal.

Operation: The circuit is biased with resistors at the base and collector to set the transistor's operating point (Q-point) in its active region. A small input AC signal (Vin) is coupled to the base through a capacitor. This small variation in base current causes a large, proportional variation in the collector current, resulting in an amplified but inverted output signal (Vout) at the collector. The voltage gain of this circuit is approximately `Av ≈ - (Rcollector / Remitter)`.

ICGOODFIND Summary

The Infineon BC817UE6327 is a highly reliable and efficient general-purpose NPN transistor that excels in both switching and amplification roles. Its robust specifications, including a 500 mA collector current rating and high transition frequency, coupled with its compact SOT-23 package, make it an indispensable component for a vast array of electronic designs, from simple driver circuits to more complex analog signal processing stages.

Keywords:

NPN Transistor

SOT-23

Switching

Amplification

Datasheet