The Bipolar Junction Transistor Let’s take a closer look at a BJT. There are 2 types of BJT’s. They are given names based on the doping content of the semiconductor chunks in each. One is called an NPN and the other is called a PNP. Each has its own electronic symbol. There is a terminal connected to each chunk of the sandwich and each terminal is given a name. Here’s a couple of tips for you: The arrow is always part of the Emitter/Base connection. The types can be identified by the direction o