BC517 (NPN Darlington Transistor)

BC517 is an NPN darlington transistor manufactured in TO-92 package, a darlington transistor is a pair of combined two BJT transistor connected with each other in a wiring called darlington pair in a single package for obtaining high gain and to switch ON higher current on very small base current.

The transistor BC517 has also a very high DC current gain as compare to other normal NPN transistors that is 30,000 due to which this device can be used as a switch where there is very small or low amount of current base current is available and where other normal BJT NPN transistors are not saturating on that small current. It can drive 1.2A load at its output which is a good feature for driving variety of loads with very small current. It will also perform well in audio amplification stages in audio circuits.