BJT and FET are electronic devices, and both are the family of transistors. Both transistors have the property of conduction as well as insulation.
BJT, as well as FET, consists of three primary terminals in it. The basic difference between BJT and FET is that BJT( bipolar junction transistor) is the bipolar and current control device. In comparison, FET (field effect transistor) is the unijunction transistor, and It is a voltage control device.
So let’s see them in more detail.
BJT vs FET
| BJT | FET |
| BJT stands for Bipolar Junction Transistor | FET stands for Field effect transistor |
| BJT is a bipolar device because the current is due to both majority carriers as well as minority carriers. | FFT is a unipolar because the current depends only on the majority carriers. |
| It is a Current control device because the input current will control the output current. | It is a voltage control device because the input voltage will determine the output current . |
| BJT has three terminals Emitter, Base and Collector | FET has three terminals Source, Gate, Drain |
| It has a low switching speed | It has a high switching speed |
| The Power dissipation is more | Low power dissipation |
| It has a low input impedance because the base is used as the common terminal. | It has a high input impedance due to the depletion region between the gate and substrate. |
| Low packaging Density | High Packaging Density |
| BJT preferred for low current application | FET are for high application |
| It has high voltage gain | It has low voltage gain |
| It has low current gain. | It has high current gain. |
| Bjt consumes more power | FET consumes less power |
| It has a negative temperature coefficient. | It has positive temperature coefficient. |
| BJT has frequency variations that affect their performance. | FET has a high-frequency response |
| BJT is cheaper than FET. | FET is a little costly than BJT |
