On 8/1/06, Gerhard Fiedler wrote: > Vasile Surducan wrote: > > >> Isn't both of this (a linear regulator providing a lower voltage for the > >> PWM, op amp driving the output) low on the efficiency scale? I still > >> think that a switcher that provides a low voltage plus maybe PWM sounds > >> like the better deal. What's the problem with this? > > > > Noise and price I think. There are only a few small noise switchers on > > the market, most of them made by Linear Technology. But probably there > > are others. My opinion is that you want an accurate sensor, then avoid > > noise. > > I understand that. But I don't know the particular sensor, and Mauricio > says that he wants to drive the sensor with unfiltered PWM... I thought if > that is compatible with the measurement principle and required precision, a > bit of ripple or noise can't hurt either. You have right. But I feel that Mauricio is far away from the ppm range. I'm wrong ? Vasile -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist