I'm skeptical of this 1% spec. The reason is that I tried to do some fast bit-banging with the PIC16C761/2, and found that there was a tiny amount of jitter with this oscillator. I calculated the jitter as being outside the 3% range at the time, although the overall oscillation kept inside the 3%. Which means its a correction-type scheme, rather than a phase-locked loop. But maybe they improved it. I've just gotten some parts, lets see what happens. --Bob At 09:56 AM 8/19/2003 -0400, you wrote: >The datasheet says +/-1% at 25C, and remember that is only a 'typical spec'. >Min and max specs are usually given for 3 sigmas from the mean, but mChip >hasn't yet documented them that I know of (the datasheet says TBD). > >Let us know what you learn. > >Bob > >----- Original Message ----- >From: "Mike Hord" >To: >Sent: Tuesday, August 19, 2003 9:42 AM >Subject: Re: [PIC:] nanoWatt PICs and OSCTUNE > > > > >Bob: > > > > > Anybody have any idea how much OSCTUNE 'pulls' the internal >oscillator > > > > > frequency in nanoWatt PICs? (like the PIC18F2320, for example). I > > > > > couldn't seem to find anything in the datasheets. > > > > > >Olin: > > > > I don't think I've ever seen a spec for that. I think the only thing > > >you > > > > can rely on is that it can pull the internal oscillator enough so that > > >one > > > > of the settings results in the specified frequency within the >specified > > > > tolerance. > > > > > >Bob: > > >I was afraid of that. > > > > > >Actually, according the datasheet I was looking at (18F2320), they don't > > >even specify a tolerance. They say +/- 1 % typical, untuned, but give no > > >maximum error. > > > > So does that imply that the error for this is +/- 1% across the entire >width > > and breadth of the temperature spectrum, or does the error begin to go > > south at temp extremes, and to a point where OSCTUNE can no longer > > tug it back into line? > > > > I guess I'll find out soon enough, because I'm working on a nanoWatt > > project now that may or may not use the internal oscillator. > > > > Mike H. > > > > _________________________________________________________________ > > MSN 8: Get 6 months for $9.95/month. > > http://join.msn.com/?page=dept/dialup > > > > -- > > http://www.piclist.com hint: To leave the PICList > > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > > >-- >http://www.piclist.com hint: To leave the PICList >mailto:piclist-unsubscribe-request@mitvma.mit.edu -------------- Bob Axtell PIC Hardware & Firmware Dev Tucson, AZ 1-512-219-2363 -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu