Post by thread:[pic]: crystals for Pics

Does anybody know the difference between a serial vs a parallel type crystal? I have tried both types and don't notice any difference, but there must be a difference, or they wouldn't be specified as parallel or serial crystals. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Yes, reading docs before asking for the help is so stupid business. Smart guys prefer reading email, rather then docs. Oscillator Design Guide: 00588B.PDF Oscillator Basics: 00826a.pdf Mike. Tim Webb wrote: > > Never mind, I guess that if I had read the rest of the email, I would have not > looked so stupid... > > and it's series not serial ha ha on me > > I must have short circuited > > {Original Message removed}

>Subject: Re: [pic]: crystals for Pics > Does anybody know the difference between a serial vs a parallel type crystal? > > I have tried both types and don't notice any difference, but there must be a > difference, or they wouldn't be specified as parallel or serial crystals. http://www.foxonline.com/ All you ever wanted to know about crystals / oscillators, and some you never thought of...;o] Regards, -Bruce spam_OUTtechTakeThisOuTrentron.com http://www.rentron.com -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

> Does anybody know the difference between a serial vs a parallel type crystal? Yup. Lots of people I suspect. > I have tried both types and don't notice any difference, > but there must be a difference, or they wouldn't be specified > as parallel or serial crystals. There is no manufacturing difference between crystals specified for series or parallel resonant application, and each will oscillate in a circuit meant for the other. There is no such thing as parallel or series "cut", although that is a commonly heard term (including in the Microchip data sheets). The difference is in the exact operating conditions required to achieve the specified frequency. There is a 90 degree phase shift difference between the parallel and series operating modes. Both points are fairly close to each other in frequency, so you might not notice the difference without an accurate measurement with a frequency counter or long term clock, for example. In theory each crystal has both a parallel and series operating point, but I've only ever seen one or the other specified. Series crystals are usually listed as "series" in catalogs, whereas parallel crystals are listed with a capacitance value, usually in the 15pF to 30pF range. This is the load capacitance required for that crystal to cause a 90 degree phase shift at the specified operating frequency. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email .....listservKILLspam@spam@mitvma.mit.edu with SET PICList DIGEST in the body