View Single Post
Old 07-27-2011, 05:34 PM   #55 (permalink)
ConnClark
DieselMiser
 
ConnClark's Avatar
 
Join Date: Jun 2008
Location: Richland,WA
Posts: 985

Das Schlepper Frog - '85 Mercedes Benz 300SD
90 day: 23.23 mpg (US)

Gentoo320 - '04 Mercedes C320 4Matic
90 day: 22.44 mpg (US)
Thanks: 46
Thanked 232 Times in 160 Posts
Quote:
Originally Posted by George Tyler View Post
the top fets need to be P-channel, and the drive needs to be inverted. you can use N-channel, but then you need common drains, not sources?
As you noted, you can use all N channel you just need to drive the gate voltage higher than what your getting in. With my charge pump circuit I can do it. Doing all N channel fets provides an advantage as they have lower on resistance.

I did look at the IR parts. I like the Linear parts more though. The national part might be the best of the lot but I can't get a simulation model of it to work.

I have a working simulation with the linear part in LTspice. It does have problems that appear to be artificial (won't let me simulate ff all fets are the same, Glitch spikes and ringing). Other than than it works quite well.

I can send it to you if you like. (it is a bit messy)
__________________
  Reply With Quote