mosfet output conversion

[AndrewT]

Originally posted by slideman82
I've read power MOSFETs had negative thermal resistance...

yes, go look at the graphs in the datasheets.
Compare Lateral to Vertical FETs and note that lateral change from positive to negative at around 100mA and that vertical change from positive to negative at enormous Amperes Id. They blow up before you can reach the negative coefficient.

Verticals need compensation. Laterals do not need it, but parallel sets do benefit from some feedback by fitting source resistors to each.

Ilimzn was referring to the uncompensated drivers.

[jmbaudoin]

Drivers have to dissipate less than 1 Watt with tipical 10 ma. bias so individual U-shaped heatsink can do balance with mos-fet thermal behavior.
The result can be DC offset less than 20mV hot/cold.

JMB

[engel dela pena]

in regards to output stage conversion if michael chua of ampslab practice this to bipolar maybe it can be done also to mosfet compare this attachment we will notice that the only difference is the the output stage

[engel dela pena]

attachment 2

[richie00boy]

Why don't you build that then? The circuit in your first post is not really suited to easy converting to n-channel mosfet by beginners.

[Workhorse]

Driving N-Channel Mosfet QC amp just like a regular bipolar QC amp is one of the biggest mistakes conducted by Diyers