BC547

The BC547 is a widely used NPN bipolar junction transistor. It is a general-purpose transistor suitable for a variety of applications in analog and digital circuits. Key characteristics include a maximum collector current of 100 mA and a maximum collector-emitter voltage of 45 V. Its DC current gain (hFE) typically ranges from 110 to 800, depending on the specific variant (e.g., BC547A, BC547B, BC547C). The transistor is housed in a small plastic package, commonly the TO-92, making it easy to use in breadboard prototyping and printed circuit boards. The BC547 is manufactured by many semiconductor companies and is readily available and inexpensive, contributing to its popularity among hobbyists and in industrial applications. Its versatility allows it to function as a switch, amplifier, or in current sources. The emitter is typically connected to the lowest potential in a circuit, the collector to a higher potential, and the base controls the current flow between them. When a small current is applied to the base, a larger current can flow from collector to emitter.