The BUL381D is a high voltage, fast-switching NPN power transistor designed for high voltage applications. It is a popular choice among engineers for its excellent performance and reliability. This discrete semiconductor component has a maximum operating voltage of 1000V and a maximum collector current of 8A. It also features a fast switching speed, making it ideal for switching power supply applications. The BUL381D is housed in a TO-220 package, which provides good thermal performance. Its low saturation voltage and high current gain further enhance its efficiency. Overall, the BUL381D is a versatile and robust component that is well-suited for a range of high voltage applications