BC848BT116

BC848BT116 Application Field and Working Principle

BC848BT116 belongs to transistors – bipolar (BJT) – single, and serves as an NPN medium frequency small signal transistor. It is typically used to amplify or switch electronic signals. Unlike FET, BJT controls the current output and gain by controlling the current input. It has low noise, high gain, medium-power gain and high input impedance, making it suitable for many applications.

Application Field

BC848BT116 is designed for applications that require a small package size, low collector-emitter saturation voltages, low voltage operation and good noise figure, such as audio and communication circuit applications, high-frequency mixers, buffer stages and audio frequencies. It is also suitable for being large collector dissipation, medium frequency amplifier and oscillator circuit, small current switch, line driver, small signal amplifier and switching applications.

Working Principle

The PN junction of the BC848BT116 is formed out of two opposedly doped semiconductor materials, namely a ‘P’ doped material and an ‘N’ doped material. An applied Voltage causes an electrical current to flow through the junction. The forward-biased is the active operating mode and the operation of the transistor is dependent upon carriers present at the base of the transistor. This will either inject into or be removed from the base-bias state and is dependant on the surrounding external circuits, thus controlling the current flow. Transistors are unidirectional devices that allow current to flow in either direction.

In a n-p-n transistor, when the base is properly biased, the amount of current at the emitter junction is much greater than the amount of current flowing into the base. This is due to the majority and minority carrier concentrations being unequal. The base current will decrease with a decrease in the base-emitter electrode voltage. This reduction of the base current will result in the collector-emitter current only being allowed to flow in one direction when the base-emitter electrode is forward bias. Thus, a small base current can control a large collector-emitter current.

BC848BT116 is an example of a Bipolar Junction Transistor (BJT) and works on the principle of the current amplification. The input signal applied to the base of the transistor controls the emitter current which, in turn, controls the collector current. This allows the output current to be much larger than the input current and hence the current gain (β) of the transistor is high. Additionally, as the BJT also has a voltage gain (α), it provides both current and voltage gains.

BC848BT116 is basically controlled by two input signals. One signal is known as the base current. The base current controls the current flow between the emitter and collector. The other signal is the base-emitter voltage. The base-emitter voltage controls the amount of current flowing into the base of the transistor.When the base is properly biased and the base-emitter voltage is increased (which causes the base current to increase), the amount of collector current is increased. The relationship between the input signals and the output signals is known as the gain of the transistor.

Thus, BC848BT116 serves as a medium-frequency small signal transistor that can be used to amplify or switch electronic signals. It features low noise, high gain, medium-power gain and high input impedance making it suitable for applications requiring a small package size, low collector-emitter saturation voltages, low voltage operation and good noise figure.