Characteristics of transistor are the graphical plots that represent the relationships between the current and the voltages of a transistor in a particular configuration. There are three important characteristics of transistor which are listed below.
- Input Characteristics:- This describes the change in input current with the changing input voltage keeping the output voltage constant.
- Output Characteristics:- This describes the change in output current with the changing output voltage keeping input current constant.
- Current Transfer Characteristics:- This describes the change in output current with the changing input current keeping output voltage constant.
Common Base (CB) Configuration of Transistor
Common base configuration of transistor is the configuration in which the base is connected in common between the input and output terminals of the transistor. This configuration offers low input impedance, high output impedance, high resistance and high voltage gain. All three characteristics of common base configuration of transformer has been explained below.
a) Input Characteristics for Common Base (CB) Configuration of Transistor
The input characteristics of a common base configuration describes the change in emitter current with changing base-emitter voltage keeping collector-base voltage constant. When graph is plotted for Ge and Si, both curves are exactly similar to the forward characteristic of a P-N junction diode. This characteristics can be used to obtain the input resistance of the transistor.
b) Output Characteristics for Common Base (CB) Configuration of Transistor
The output characteristics for common base configuration of transistor describes the change in collector-current with collector-base voltage keeping emitter current constant.
c) Current Transfer Characteristics for Common Base (CB) Configuration of Transistor
The current transformer characteristics for a common base configuration of transistor describes the change in collector-current with the changing emitter-current keeping base voltage constant. The resulting current gain has a value less than 1.
Common Collector (CC) Configuration of Transistor
a) Input Characteristics for Common Collector (CC) Configuration of Transistor
b) Output Characteristics for Common Collector (CC) Configuration of Transistor
c) Current Transfer Characteristics for Common Collector (CC) Configuration of Transistor
Common Emitter (CE) Configuration of Transistor
a) Input Characteristics for Common Emitter (CE) Configuration of Transistor
b) Output Characteristics for Common Emitter (CC) Configuration of Transistor
The output characteristics for common emitter configuration of transformer describes the change in collector current with changing collector emitter voltage keeping base current constant.
c) Current Transfer Characteristics for Common Emitter (CE) Configuration of Transistor
The current transfer characteristics for common emitter configuration of transistor describes the change in collector current with changing base current keeping collector emitter voltage constant. The collector-emitter current gain is always greater than 1.