I know just enough to think this device may be of interest for fan control. Came across it in a trade pub. Maybe it is the answer to some of the pmw controller shortcomings? Have a look and let us know please. http://www.melexis.com/prodmain.asp?search=us168&family=US168 Thanks
The problem is that not many nerds actually build their own fans, and it would probably be hard to replace existing fan drivers inside fans because of different pinouts.
The new 4-pin fans can help reduce PWM noise, they separate motor supply from electronics supply. More here.
IMO, you can get rid of PWM problems by using a power emitter-follower circuit. Its linear, its cheaper, its easier. And you can use a digital pot to make it fancy.
