BC817

The BC817 is a widely used NPN bipolar junction transistor (BJT) manufactured by Changjiang Electronics, among other companies. It is designed for general-purpose switching and amplification applications. Here’s a detailed description of its characteristics and specifications:

Physical Characteristics:

• Package Type: The BC817 typically comes in a TO-92 package, which is a cylindrical plastic housing with three leads extending from the bottom. This package is compact and suitable for through-hole mounting on printed circuit boards (PCBs).
• Lead Configuration: The three leads are usually arranged in a specific order: the emitter (E), base (B), and collector (C). The pinout is essential for proper circuit integration.

Electrical Characteristics:

• Maximum Collector-Emitter Voltage (Vce): The BC817 can handle a maximum voltage of around 45V, making it suitable for various low to moderate voltage applications.
• Maximum Collector Current (Ic): It can support a maximum collector current of approximately 800mA, allowing it to drive small loads effectively.
• DC Current Gain (hFE): The transistor exhibits a current gain (hFE) ranging from 100 to 800, depending on the specific operating conditions. This high gain makes it efficient for amplification purposes.
• Transition Frequency (fT): The BC817 has a transition frequency of about 100 MHz, which indicates its capability for high-frequency applications.

Thermal Characteristics:

• Junction Temperature (Tj): The maximum junction temperature is typically around 150°C, which allows for operation in various environmental conditions.
• Thermal Resistance: The thermal resistance from junction to ambient is relatively low, ensuring efficient heat dissipation during operation.

Applications:

The BC817 is versatile and can be used in a variety of applications, including:

• Switching Circuits: It is commonly used in low-power switching applications, such as driving relays, LEDs, and small motors.
• Amplification: The transistor is suitable for audio and radio frequency amplification due to its high gain and frequency response.
• Signal Processing: It can be employed in signal processing circuits, including oscillators and amplifiers in communication devices.

Additional Features:

• Low Noise: The BC817 is designed to operate with low noise levels, making it ideal for audio and sensitive signal applications.
• Cost-Effective: As a widely used component, it is generally available at a low cost, making it accessible for hobbyists and professionals alike.

In summary, the BC817 from Changjiang Electronics is a reliable and versatile NPN transistor suitable for a wide range of electronic applications, characterized by its compact size, robust electrical specifications, and cost-effectiveness.