Small Signal Transistor
Small signal transistor, fully known as a semiconductor triode, also known as a bipolar transistor and a triode transistor, is a kind of semiconductor component for controlling current to amplify weak signals into electrical signals with larger amplitude, and it is also used as a contactless switch. As one of the basic semiconductor components, a triode transistor is the core component of an electronic circuit for current amplification. A triode is made of two PN junctions that are very close to each other on a semiconductor substrate. The two PN junctions divide the whole semiconductor into three parts. The middle part is the base region, and the two sides are the emitter region and the collector region. The arrangement modes are PNP and NPN.