Product Description
The BC557 (RM0385) is a PNP transistor and a heavy-duty drop-in replacement for a 2N2222 or 2N3906. The three terminals of a bipolar transistor are called the emitter, base, and collector. A small current into the base controls a large current flow from the collector to the emitter. The current at the base is typically one-hundredth of the collector-emitter current. Moreover, the large current flow is almost independent of the voltage across the transistor from collector to emitter.