Infineon BCW61DE6327 NPN Bipolar Junction Transistor: Datasheet, Pinout, and Application Circuits
The Infineon BCW61DE6327 is a general-purpose NPN bipolar junction transistor (BJT) housed in a compact SOT-23 surface-mount package. Designed for a variety of amplification and switching applications, this component is a reliable choice for modern electronic designs where space and efficiency are critical.
Datasheet Overview and Key Specifications
The BCW61DE6327 is characterized by its high current gain, making it highly efficient for amplifying small signals. Key absolute maximum ratings from its datasheet include a collector-emitter voltage (VCE) of 45 V and a continuous collector current (IC) of 500 mA. The device's power dissipation is 330 mW, which is standard for the SOT-23 package.
Its electrical characteristics are defined by a DC current gain (hFE) that ranges from 125 to 400 at a collector current of 10 mA, ensuring strong amplification capabilities. The transistor also features a low collector-emitter saturation voltage, typically around 250 mV, which is crucial for switching applications as it minimizes power loss in the "on" state. The transition frequency is 100 MHz, indicating its suitability for low-frequency amplification tasks.
Pinout Configuration
The SOT-23 package has three pins. When viewing the component with the flat side facing you and the pins downward:
Pin 1 (Emitter - E): This is the source of electrons.
Pin 2 (Base - B): This terminal controls the transistor's operation.
Pin 3 (Collector - C): This is the terminal where electrons are collected.
It is vital to confirm this pinout with the manufacturer's datasheet for your specific lot, as pin configurations can occasionally vary between different transistor part numbers.
Common Application Circuits
1. Low-Side Switch: The most common use for the BCW61DE6327 is as a low-side switch to control loads like LEDs, relays, or motors. A small control current from a microcontroller (e.g., an Arduino GPIO pin) is applied to the base through a current-limiting resistor (e.g., 1-10 kΩ). This allows a much larger current to flow from the collector to the emitter, turning on the load connected to the collector pin and a positive supply rail. A flyback diode is essential when driving inductive loads like relays to protect the transistor from voltage spikes.
2. Small Signal Amplifier: The transistor can be configured in common-emitter amplifier circuits to amplify voltage or current from sensors such as microphones or photodiodes. The high hFE of the BCW61DE6327 makes it effective for boosting weak analog signals before they are processed by another stage of a circuit. Proper biasing of the base terminal is required to set the transistor's operating point for linear amplification.
3. Darlington Pair Driver: For applications requiring even higher current gain, two transistors can be arranged in a Darlington pair configuration. The BCW61DE6327 can serve as the second transistor in the pair, dramatically increasing the overall sensitivity to very small input currents.
ICGOODFIND Summary
The Infineon BCW61DE6327 is a versatile and robust NPN transistor ideal for a wide array of general-purpose amplification and switching tasks. Its combination of high current gain, low saturation voltage, and a compact SOT-23 package makes it an excellent component for space-constrained PCBs in consumer electronics, automotive modules, and industrial control systems. Designers value its reliability and performance in controlling loads and processing small signals efficiently.
Keywords: NPN Transistor, SOT-23 Package, Low-Side Switch, Current Gain, Saturation Voltage
