The Cut-Off region is also called a Pinch-off region where the gate voltage Vgs is enough to force the JFET to behave as an open circuit since the resistance of the channel is maximum. In the ohmic region when Vgs = 0 the JFET will behave as a voltage-controlled resistor and carries a very small depletion layer of the channel. The following figure shows the characteristics curves of JFETs: In the case of N-Channel JFET, charge carriers are electrons, while they are holes in the case of P-Channel JFET. The only difference is the charge carriers. This is the working of N-Channel JFET that works similar to P-Channel JFET. However, when the reverse-biased voltage on the gate terminal is decreased, it would also decrease the depletion layer width, and as a result, the conducting channel width would increase. Hence, the current from source to drain terminals reduces. This results in reducing the conduction channel width and would increase n-type bar resistance. The depletion layer width increases when the reverse voltage is applied across Vgs gate and source terminals. The channel width and current conduction through the bar are determined by the size of the depletion layers. As a result, electrons flow from source to drain terminal through a channel that stands between the depletion layers. In this case, the two pn-junction across the bar sides generates a depletion region. In case 1, the voltage at the gate pin is zero, and voltage Vds is applied between drain and source terminal as shown in the figure below. The working of N-Channel JFET can be described as follows by taking two different cases: Case 1: The current-carrying path that exists between the source and drain terminals is known as “channel” which can be composed of either N-type or P-type semiconductor material. The conductivity process is controlled by applying the input voltage at the gate terminal. The FET is an electronic device that contains charge carriers, either electrons or holes that flow from source to drain terminals through the active channel. The following figure shows the symbol of MOSFET and JFET transistors that are the two main types of FET transistors. The low power consumption and low power dissipation make this device an ideal fit for integrated circuits. FET transistors usually come with high input impedance at low frequencies and display instant operation, high operation, are robust and cheap, and are used in many electrical circuits. But conduction process doesn’t involve both charge carriers at the same time. In FETs, either holes or electrons are used for the conduction process. Gate: This terminal controls the conductivity between source and drain terminals.įETs are also known as unipolar transistors as opposed to BJTs that are bipolar transistors.Drain: It is a terminal through which charge carriers leave the channel.Source: It is a terminal through which charge carriers enter the channel.The three terminals in this device are named drain, source, and gate. The FET(Field Effect Transistor) is a three-terminal electronic device used to control the flow of current by the voltage applied to its gate terminal. I’ll walk you through the FET (Field Effect Transistor) in detail and cover each and everything related to FET including FET definition, symbol, working, characteristics, types, and applications.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |