2N5401 High-Voltage, Low-Power PNP Silicon Transistor Housed In A TO-92 Package, Featuring A 150V Collector-Emitter Voltage Rating

A PNP bipolar junction transistor rated at 150V collector-emitter and 600 mA collector current, used for high voltage low power switching, where its 150V rating handles circuits that would destroy an ordinary small signal transistor. As a PNP device it conducts when its base is pulled low, which suits high side switching from a positive rail. Always fit a base resistor when driving it from a microcontroller pin - connecting a base directly to a logic output will damage both. A common starting value is 1K for switching applications. 150V and 600 mA rating suits moderate loads; TO-92 through-hole package fits breadboards; Very low cost and widely documented; Standard pinout for the 2N5401 family