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28 May 2018

Difference between JFET and MOSFET

Before we learn about the difference between JFET and MOSFET first let we understand the full meaning of JFET and full meaning of MOSFET. Basically, JFET and MOSFET are types of FET which is a group of field effect transistor, devices the operation of which is connected with electrostatic modulation of conductivity between the source and drain. JFET and MOSFET both devices can be used as switches and amplifiers. Here this article gives information about the difference between JFETs and MOSFET to know more details about it.

Difference between JFET and MOSFET | JFET vs MOSFET

  • JFET called for junction field-effect transistor, MOSFET called for metal oxide semiconductor field-effect transistor.
  • JFET operated only depletion mode, MOSFET operates in both enhancement and depletion mode.
  • JFET has two P-N junctions, MOSFET has only one P-N junction.
  • JFET is three-terminal devices while MOSFET is four-terminal devices.
  • JFET does not form the capacitance at the channel but in MOSFET capacitor in between channel and gate.
  • JFET is a simple manufacturing process but MOSFET is a difficult manufacturing process.
  • JFET is a conductivity is a control by the reverse biasing of the gate whereas  MOSFET is conductivity is controlled by the carrier induced in the channel.
  • JEFT is a high input impedance while MOSFET is a very high input impedance.
  • JFET is a more flat characteristics curve while MOSFET has less flat characteristics curve.
  • JFET is normally ON the device, MOSFET is normally OFF devices.
  • MOSFET has a reverse body diode, In JFET has no reverse body diode. 
  • JFET is a high gate current while MOSFET is a low gate current.
  • JFET is a high drain current but MOSFET is a low drain current.
  • JFET gate is not insulated from the channel while MOSFET is insulated from the channel.
  • In the JFET channel and gate forms two P-N junctions but in the MOSFET channel and gate from two parallel capacitors.
  • In JFET signal handling capacity is less, in MOSFET signal handling capacity is more.
  • In JFET fabrication is complex and costly but in MOSFET has easy to fabricate and cheap.
  • JFET has a higher drain resistance compared to MOSFET.
  • Leakage current in MOSFET is less than to JFETs.
  • MOSFET is easier to construct and widely used compared to JFETs.
  • JFET is mostly used in low noise applications, MOSFET is mostly used in high noise applications.
  • JFET is power classification is more compared to MOSFET.
  • JFET is a gate margin of around 0.1 to 10 mA/v while in MOSFET has a gate margin around 0.1 to 20 mA/v.
  • JFET is less popular than MOSFET devices and also have MOSFET is widely used today than JFETs.
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