Self on Audio, 2nd Edition

15

FETs versus BJTs: the linearity competition

This short chapter was published when debate about the linearity of power FETs was raging, or at any rate smouldering, in the letters columns of Electronics World. Many contributors were content to point out that FETs must be more linear than bipolar transistors because everyone says so. This sort of argument has never had much appeal for me, and I carried out several investigations to see if there was any way in which FETs could be claimed to produce less distortion. One of the problems with this is making a meaningful comparison between two rather different kinds of active device. Here I try to level the playing field by making the transconductances the same; the BJT wins heavily on linearity when ...