CFP with N-channel mosfet and PNP?


2005-02-11 1:25 pm
AudioGeek said:
Just wondering where there is a schematic of a CFP output stage with N channel MOSFETS and the BJT driver stage?

Searched and saw P-channels with BJT's and BJT's with BJT's.

Can someone point me in the right way or draw up a schema quickly?


I don't see what the problem is - if you have seen BJT with P-ch MOSFET, just copy it symetrically to BJT and N-CH MOSFET. Such a stage behaves as a BJT stage as far as driving is concerned, the bias and thermal compensated is the same as for a BJT CFP stage.
Although a BJT-MOS CFP looks very interesting (high gm but MOSFET ruggedness), it also suffers from MOSFET Vgs rail loss, and this cannot be easily avoided (unlike simple follower where higher driver rails solve the problem).