Difference between JFET and BJT

One of the major difference between JFET and BJT is that JFET is a unipolar device while BJT is a bipolar device. Here this article gives information about the difference between JFET and BJT to know more details about it.
  • The JFET stands for junction field effect transistor while BJT stands for bipolar field effect transistor.
  • JFET is uni-polar device, BJT is a bipolar devices.
  • JFET is the low noise level, BJT is the high noise level.
  • In JFET the operation depends on the control of a junction depletion with under reverse bias while in BJT the operation depends on the injection of minority carrier across the forward bias junction.
  • JFET voltage control device while BJT is current control device.
  • JFET easily damaged by static, BJT is robust.
  • JFET is better thermal stability but  BJT is less thermal stability.
  • JFET is high input impedance, BJT is low input impedance.
  • JFET has high current gain, BJT has a low current gain.
  • JFET has low voltage gain whereas BJT has high voltage gain.
  • JFET has high output impedance, BJT has a low output impedance.
  • JFET has fast switching time while BJT has medium switching time.
  • JFET is difficult to bias but BJT has easy to bias.
  • JFET is more expensive compare to BJT.
  • JFET is less noisy while BJT is much noisy than FET.
  • JFET is high frequency response but in BJT frequency variation effects the performance.
  • Gain is characterized by trance-conductance using JFET, in BJT characterized by voltage gain.
  • JFET has small gain bandwidth product while in BJT bandwidth is grater than FET.
  • JFET has no offset voltage, so it work better as a switch or chopper, BJT has always an offset voltage before switching.
  • BJT is bigger than FET.