BC858BW-G

BC858BW-G transistors are part of the semiconductor family known as bipolar junction transistors (BJT). They are a single device, meaning they consist of only one active layer, instead of double or triple layers as some other transistors. This type of transistor works by controlling the current flow between two nodes, called the emitter, collector and base. To control current flow, the advantage of BJTs is that it is generally much simpler and easier to do than for other types of transistors.

Application

BC858BW-G can be used in many applications, including power supplies, audio amplifiers, and signal switching. They are best suited for applications where low noise and high efficiency are important, such as portable audio applications, laptop power supplies, and automotive circuit designs.

Working Principle

A BJT, such as the BC858BW-G, works by using a current flowing between two nodes, the emitter and collector. This current is controlled by a voltage applied to the base node. As the voltage and current flowing between the emitter and collector increase, the collector current will start to decrease. This decrease in current occurs because the base-collector junction of the transistor starts to become more heavily doped, causing a reduction in the potential barrier between the collector and emitter.

The overall effect of this is to reduce the current flowing between the collector and emitter, and hence the voltage across it. This voltage, or base current, is what is known as the transistor’s switching speed. The faster the transistor is switched on and off, the higher the voltage and current it will be able to carry, which means the transistor will be able to perform better.

In summary, when an input voltage is applied to the base of the transistor, this voltage is used to control the current flow between the emitter and collector. As the base-collector junction becomes more heavily doped, this reduces the potential barrier between the collector and emitter, thus reducing the current flowing between them.

By regulating the current flow from the collector to the emitter, the transistor can be used to amplify signals, switching them on and off quickly, and amplifying the signal levels. BC858BW-G transistors can therefore be used in many applications, from audio amplifiers to power supplies, due to their high switching speed and excellent efficiency.