Answer to Question #278895 in Electrical Engineering for Tania Akter

Question

a. Draw JFET transfer characteristics curve with appropriate details. 

b. How a MOS-FET work better than JFET, describe it with appropriate diagram

Answer 1

MOSFET: stands for Metal Oxide Semiconductor Fiel Effect Transistor.

MOSFET is a voltage-controlled device and the output current varies as a function of a small voltage applied to its gate. The electrostatic field of the gate is impinging on and affecting the resistance of the source-to-drain channel of the device, therefore, the term field-effect transistor.

 

IGBT: Insulated Gate Bipolar Transistor. They are voltage-controlled device, and output current is a function of a small voltage applied to its gate. The control signal voltage modulates a channel resistance which in turn also varies the number of current carriers (both electrons and holes) available to carry current from the emitter terminal to the collector terminal.

MOSFET operates in either enhancement mode or depletion mode along with higher input impedance compare to FET.

Also, high drain resistance due to lower resistance of channel is added advantage with MOSFET over FET.