BC857,235

Introduction

BC857,235 is a type of bipolar junction transistors (BJT). Single-transistor BJTs are most commonly used in amplifier and switching circuits because of their simple design, small size and low cost. They can be used as switches, amplifiers and amplifiers of small signals. The working principal of the BC857,235 is to control current by using the base current and the biasing voltage.

Structure

The BC857,235 is a three-terminal device, with two semiconductor junctions, composed of a P-type semiconductor layer between two N-type semiconductor layers. The terminals are the emitter (E), base (B), and collector (C). The base and collector are on the N-type layers, while the emitter is the P-type layer. Current is carried by electrons moving in the N-type layer, while the B-C junction isolates the emitter and collector.

Operation

The BC857,235 is a current-controlled device, meaning that the base current controls the flow of current from the collector to the emitter. The current flow is enabled by applying a biasing voltage to the base-emitter junction. The biasing voltage can be either positive or negative, and the direction of current flow is determined by the polarity of the voltage. The magnitude of the current from the collector to the emitter can be varied by changing the current through the base.

Applications

Bipolar junction transistors are commonly used as amplifier and switching circuits. In amplifiers, they can be used as an active component to increase the gain of a signal. They can also be used as switches, allowing a single small control current to switch a much larger current. The BC857,235 can be used in a variety of low-power applications, such as audio amplifiers, analog-to-digital converters, video amplifiers, and digital logic.

Conclusion

The BC857,235 is a single bipolar junction transistor (BJT) commonly used in amplifier and switching circuits because of its simple design, small size and low cost. It is a three-terminal device with two P-N junctions and is used for controlling current. The magnitude of the current is determined by controlling the current through the base and the biasing voltage applied to the base-emitter junction. It is used in a variety of low-power applications, such as audio amplifiers, analog-to-digital converters, video amplifiers, and digital logic.