The input is a Gate that is essentially infinite impedance, so no current. The output is essentially the resistance between Source and Drain, which controls the current flowing through it.
FET stands for Field Effect Transistor. The name FET comes because the gate current of a field effect transistor is zero and current present in the source conductor is due to an electric field produced by the substrate material placed between the gate and the source.
The input of a transistor is typically referred to as the "gate" in a field-effect transistor (FET) or the "base" in a bipolar junction transistor (BJT). In both cases, the input controls the flow of current through the transistor, allowing it to function as a switch or amplifier in electronic circuits. The gate or base receives the input signal that modulates the transistor's operation.
since in an FET the value of the current depends upon the value of the voltage applied at the gate and drain...so it is known as voltage controlled device.. for example..in a mosfet..the current from drain to source depends upon the width of the depletion layer..which in turn depends upon the voltage applied on the gate.. so that is the reason
BJT is a current controlled device because its output current is dependent upon the current in the base while for FET it is controlled by the voltage at the gate terminal of the transistor. BJT is a current controlled device because its base current is not zero while for a FET the gate current is zero
Gate current is denote by Ig
The input is a Gate that is essentially infinite impedance, so no current. The output is essentially the resistance between Source and Drain, which controls the current flowing through it.
Gate
FET stands for Field Effect Transistor. The name FET comes because the gate current of a field effect transistor is zero and current present in the source conductor is due to an electric field produced by the substrate material placed between the gate and the source.
The input of a transistor is typically referred to as the "gate" in a field-effect transistor (FET) or the "base" in a bipolar junction transistor (BJT). In both cases, the input controls the flow of current through the transistor, allowing it to function as a switch or amplifier in electronic circuits. The gate or base receives the input signal that modulates the transistor's operation.
since in an FET the value of the current depends upon the value of the voltage applied at the gate and drain...so it is known as voltage controlled device.. for example..in a mosfet..the current from drain to source depends upon the width of the depletion layer..which in turn depends upon the voltage applied on the gate.. so that is the reason
fet is a voltage controlled device...cut off voltage in fet refers to that voltage of the gate - source junction at which the current flow through channel is zero
fet is a voltage controlled device...cut off voltage in fet refers to that voltage of the gate - source junction at which the current flow through channel is zero
A FET (Field Effect Transistor) is mainly used when the input signal needs to be isolated from the output. A FET has a very high input resistance, so very little current is required from the input. Voltage gain is not the main objective when using a FET.
BJT is a current controlled device because its output current is dependent upon the current in the base while for FET it is controlled by the voltage at the gate terminal of the transistor. BJT is a current controlled device because its base current is not zero while for a FET the gate current is zero
the gate is insulated from the channel by either a reverse biased junction or silicon dioxide.
The Gate.