Application level difference between BJT, FET

[demetal]

Hi,

What are the basic difference in application of BJT,FET,MOSFET and IGBT.... i.e; for example all this are used for switching applications but in some circuits BJT wont work but a MOSFET will... also i would like to know the pros and cons for each if used in different situations....

Thanks

 

[goldsmith]

Hi,

What are the basic difference in application of BJT,FET,MOSFET and IGBT.... i.e; for example all this are used for switching applications but in some circuits BJT wont work but a MOSFET will... also i would like to know the pros and cons for each if used in different situations....

Thanks

Hi demetal
A mosfet or IGBT has a big advantage which is pretty high input impedance and faster speed of switching . but bjts are slower and of course with lower powers and you have to inject them high value of current . it is enough that you think that you need a 500A square wave , current . and your bjt has beta of 35 ! you have to use them as a long chain ( darlington pairs ) ro increase hfe . and it will be cause of gang of problems .
And about IGBT , IGBTs are slower than mosfets but their dissipation is lower than mosfets ! ( IGBT is derived from mixture between a BJT and a mosfet )
Best Wishes
Goldsmith