Are tolerance and accuracy same? bala On Thu, Dec 15, 2011 at 2:15 PM, Jayaprabakaran < jayaprabakaran.k@xxxxxxxxxxxxxxxxxxx> wrote: > Hi Hilal and Vikas, > > > Thanks for the clarification. > > > > Regards, > > Jp > > > > _____ > > From: vikas dhanda [mailto:vikasdhanda7@xxxxxxxxx] > Sent: Thursday, December 15, 2011 1:14 PM > To: Jayaprabakaran > Cc: si-list@xxxxxxxxxxxxx > Subject: Re: [SI-LIST] Re: ppm(parts per million)-Crystal OSC > > > > Frequency tolerance (in ppm)=>The Frequency Tolerance of a crystal or > oscillator is defined as the initial deviation of the crystal or oscillator > frequency as compared to the absolute at 25°C like it designed for 25Mhz > but > measured is 24.999946Mhz So this is the frequency tolerance. > > > > Where the > > > Frequency stability is the frequency deviation compared to the measured > frequency at 25°C over the defined operating temperature and voltage > range.Here we consider 24.999946Mhz as actual frequency (as Measured) and > calculate PPM with this Frequency but don't consider 25Mhzfor calculation. > > > > > > Regards, > > Vikas Dhanda > > On Thu, Dec 15, 2011 at 10:25 AM, Jayaprabakaran > <jayaprabakaran.k@xxxxxxxxxxxxxxxxxxx> wrote: > > > Most of the crystals have two ppm values. > Frequency tolerance (in ppm) and Frequency stability (in ppm). > What are the difference b/w two parameters? > > Regards, > Jayaprabakaran > > > -----Original Message----- > From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] > On > > Behalf Of Mike Poorman (Cascade Engineering Svcs Inc) > Sent: Wednesday, December 14, 2011 11:22 PM > To: 'si-list@xxxxxxxxxxxxx' > Subject: [SI-LIST] Re: ppm(parts per million)-Crystal OSC > > Think of PPM as a tolerance on the frequency. The smaller the PPM number > the more accurate and stable the crystal frequency will be. > > Mike Poorman > EMC Technician > Cascade Engineering Services, Inc., > Email: v-mipoor@xxxxxxxxxxxxx > > This email message may contain confidential and proprietary information. > Any unauthorized use is prohibited. If you are not the intended recipient, > please contact the sender by reply email and destroy all copies of the > original message. > > > > -----Original Message----- > From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] > On > Behalf Of bala > Sent: Wednesday, December 14, 2011 2:17 AM > To: si-list@xxxxxxxxxxxxx > Subject: [SI-LIST] ppm(parts per million)-Crystal OSC > > Hi all, > I have a little confusion on PPM vs frequency of Crystal Oscillators.How > important is the term 'ppm' than frequency.Why all the datasheets have both > units,ppm and Hz.Please clarify,Also how much important is the value of ppm > on the Signal integrity side,if any.Thanks for your time. > > -- > bala > > > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > > List technical documents are available at: > http://www.si-list.net <http://www.si-list.net/> > > List archives are viewable at: > //www.freelists.org/archives/si-list > > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > > > > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > > List technical documents are available at: > http://www.si-list.net <http://www.si-list.net/> > > List archives are viewable at: > //www.freelists.org/archives/si-list > > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > > > > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > > List technical documents are available at: > http://www.si-list.net <http://www.si-list.net/> > > List archives are viewable at: > //www.freelists.org/archives/si-list > > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > > > > > > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > > List technical documents are available at: > http://www.si-list.net > > List archives are viewable at: > //www.freelists.org/archives/si-list > > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > > -- bala ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List technical documents are available at: http://www.si-list.net List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu