Difference between triode BJT and FET

There are many differences between triode BJT and FET, which are listed as follows:
1. The triode is controlled by current. The MOS tube belongs to voltage control. The BJT amplifies the current, and the FET converts the grid voltage into drain current. The first parameter of BJT is current magnification β Value, the first parameter of FET is GM;
2. Driving capacity: MOS tube, common power switch tube and high current local switch circuit;
3. Cost: triode is cheap and MOS is expensive;
4. BJT has poor linearity and FET has good linearity;
5. BJT noise is large and FET noise is small;
6. BJT polarity is only NPN and PNP. FET polarity includes n-channel, p-channel, depletion type and enhancement type, so FET selection and use are complex;
7. Power consumption: BJT input resistance is small and consumes large current, while FET input resistance is large and hardly consumes current;
In fact, triode is relatively cheap and easy to use. It is often used in digital circuit switch control; MOS transistor is used in high-frequency and high-speed circuits, high current occasions, and places sensitive to base or drain control current.
In general, it is a general trend for FET to replace BJT in both discrete component circuits and integrated circuits.

Commax-Tech Electronic Co., Ltd      Electronic component specialist

B23, second floor, ASEAN building, Longhua District, Shenzhen

sales@commax-tech.com

https://commax-tech.com

Keyword：Triode BJT   FET   MOS   Commax-Tech Electronic