BC559 BJT PNP Transistor TO-92⚡

The BC559 is a small-signal PNP bipolar junction transistor (BJT) in a compact TO-92 package, ideal for amplification and switching in low-power analog and digital circuits. With a high DC current gain (hFE), low VCE(sat), and a transition frequency up to 150 MHz, it’s a dependable choice for electronics components used in projects with microcontroller-based modules.

Key Features 🔧

• PNP transistor for high-side switching and signal amplification
• High current gain (hFE 110–800) for efficient small-signal amplification
• Low saturation voltage for improved switching efficiency
• Good high-frequency performance with ft up to 150 MHz
• TO-92 package for easy breadboarding and through-hole assembly
• Reliable and robust construction for long-term use

Technical Specifications 📊

• Transistor Type: BJT PNP
• Package Type: TO-92
• Collector-Emitter Voltage (VCEO): -30 V
• Collector-Base Voltage (VCBO): -30 V
• Emitter-Base Voltage (VEBO): -5 V
• Collector Current (IC): -100 mA
• Power Dissipation (PD): 500 mW
• DC Current Gain (hFE): 110 to 800
• Transition Frequency (ft): 150 MHz

Typical Applications 🔌

The BC559 is versatile and suitable for a wide range of circuits, including:

• Audio amplification stages
• Signal processing and conditioning
• Power management and control
• Switching circuits (high-side, low-power)
• General-purpose amplification in analog modules

Integration with Development Boards 🧩

Works seamlessly in Arduino, Raspberry Pi, ESP32, and other microcontroller-based projects for tasks such as level shifting, sensor interface buffering, and low-current high-side switching. Always include an appropriate base resistor and observe voltage/current limits.

Design Notes and Pinout ⚠️

• Typical TO-92 orientation places leads as Collector–Base–Emitter when viewed from the flat side, but pinouts can vary by manufacturer. Verify against the specific datasheet before assembly.
• Keep within the stated maximum voltage, current, and power dissipation ratings.
• For microcontroller interfaces (e.g., Arduino/Raspberry Pi), use a base resistor and consider a pull-up on the emitter/collector as required by the circuit topology.