On Sun, 11 Jan 2004 20:19:16 -0600, James Nick Sears=20 wrote: > > From here I think the problem should be pretty well defined in the last= =20 > post > you replied to. Basically the LT1790 will not put out the proper 1.25V > output if it is powered up every second and will fail (output barely=20 > rises) > every other second. > > Thanks, > Nick > It should however.. you shouldn't be attempting to turn it on every secon= d=20 as acording the page 18 of the data sheet it has a 685ms turn on time. =20 What this means is it must be on 70% of the time at least and you should=20 sample at the end of the 70% turn it off wait 30% of the time then turn i= t=20 on so the supply settles. Turn on time will vary depending on what=20 capacitor you placed on it, acording to the sheet it's 1uF optimized. If= =20 50 to 80uA for a micropower reference isn't a big deal, I suggest leaving= =20 it on and saving yourself some suffering. Of course if you plan to use th= e=20 pin for something else, that might be a problem. --=20 Stephen R. Phillips was here -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.