The FFB3904 is a popular NPN bipolar junction transistor (BJT) that belongs to the discrete semiconductor component family. It is designed for general-purpose amplification and switching applications in electronic circuits. The key features of the FFB3904 include a maximum collector current of 200mA, a maximum collector-base voltage of 40V, and a maximum DC current gain of 300. This transistor is housed in a small SOT-23 surface-mount package, making it suitable for compact designs. It has a low noise figure and high gain, making it ideal for low-power amplification applications. The FFB3904 is commonly used in audio amplifiers, signal processing circuits, and voltage regulators. Overall, it is a reliable and versatile component that is widely used in various electronic devices