Infineon BCX42E6327HTSA1 NPN General Purpose Transistor: Datasheet, Pinout, and Application Circuits
The Infineon BCX42E6327HTSA1 is a high-performance NPN bipolar junction transistor (BJT) designed for general-purpose amplification and switching applications. Housed in a compact SOT-23 surface-mount package, this device is engineered for high current gain and low saturation voltage, making it an excellent choice for a wide range of electronic circuits, from consumer electronics to industrial control systems.
Datasheet Overview and Key Specifications
The transistor's datasheet provides essential information for designers to integrate it effectively into their projects. Key maximum ratings and characteristics include:
Collector-Emitter Voltage (VCE): 45 V
Collector Current (IC): 300 mA
Total Power Dissipation (Ptot): 330 mW
DC Current Gain (hFE): Ranges from 40 to 250 (typically around 120 at IC=10 mA, VCE=1 V), highlighting its high amplification capability.
Transition Frequency (fT): 150 MHz, indicating its suitability for low to medium-frequency amplification.
A critical feature is its low collector-emitter saturation voltage (VCE(sat)), which is typically only 50 mV at IC=10 mA and IB=0.5 mA. This low VCE(sat) ensures minimal power loss when the transistor is in its fully-on (saturated) state, which is crucial for efficient switching applications.
Pinout Configuration
The BCX42E6327HTSA1 comes in a SOT-23 package with three pins. When viewing the flat side of the component:
1. Pin 1 (Emitter - E): This is the source of electrons.
2. Pin 2 (Base - B): This pin controls the transistor's operation. A small current here controls a larger current between the collector and emitter.
3. Pin 3 (Collector - C): This is where the main current flows through.
Correctly identifying this pinout is absolutely critical to avoid damaging the component during circuit assembly.
Application Circuits
The BCX42E6327H6327HTSA1 is versatile and can be used in two primary modes: as a switch and as an amplifier.
1. Switching Circuit (Interface/Driver):
A common use is to drive a relay, LED, or small motor from a microcontroller (e.g., an Arduino or ESP32). A microcontroller's GPIO pin can only supply a limited current (e.g., 20 mA), which is insufficient for these loads.
How it works: The microcontroller's output pin is connected to the base of the transistor through a current-limiting resistor (e.g., 1-10 kΩ). The load (e.g., a relay coil) is placed between the positive supply voltage and the collector pin. The emitter is connected to ground.
Operation: When the microcontroller outputs a HIGH signal (e.g., 3.3V or 5V), a small current flows into the base, switching the transistor fully on. This creates a low-resistance path between the collector and emitter, allowing the larger required current to flow through the load, activating it. The low VCE(sat) ensures most of the voltage is dropped across the load itself.
2. Amplifier Circuit (Common Emitter):
The transistor can be configured as a voltage amplifier for small AC signals, such as from a microphone or sensor.
How it works: A voltage divider network (two resistors) at the base sets the DC operating point (quiescent point). An emitter resistor provides stability against temperature variations. A collector resistor converts the amplified current into a varying output voltage. Input and output capacitors (C1 and C2) are used to block DC bias while allowing the AC signal to pass.
Operation: A small alternating current applied to the base terminal is amplified, resulting in a much larger alternating current at the collector. The voltage gain of this circuit is determined by the ratio of the collector resistor to the emitter resistor.
ICGOODFIND: The Infineon BCX42E6327HTSA1 is a robust and highly efficient NPN transistor that excels in both switching and amplification roles. Its standout features of high current gain, low saturation voltage, and operation at medium frequencies make it an ideal and reliable component for designers seeking to optimize power efficiency and performance in modern electronic designs.
Keywords: NPN Transistor, General Purpose, Low Saturation Voltage, High Current Gain, SOT-23 Package.
