2N2222 NPN Bipolar Junction Transistor (BJT) Used For General-Purpose Low-Power Amplifying And Switching

A NPN bipolar junction transistor rated at 40V collector-emitter and 800 mA collector current, used for general purpose switching and amplification - one of the most widely specified transistors in textbooks and reference designs worldwide. As a NPN device it sinks current to ground when its base is driven high. 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. 40V and 800 mA rating suits moderate loads; TO-92 through-hole package fits breadboards; Very low cost and widely documented; Standard pinout for the 2N2222 family