>What sort of accuracy does one get with various clocks (not including RC) >for a PIC? For MIDI serial, the specs call for 1% timing accuracy. What sort >of difficulty will there be in getting a clock to this accuracy? A resonator will easily meet these specs. Murata and others provide details on web. Off the cuff resonators give you about 0.1% across temperature and crystals are 10+ times better across temperature. Try www.murata.com/develop/index.htm > Is there >any difference in accuracy (or other specs) between a resonator and a >crystal (or diff. types of crystal? Cheapest available "microprocessor crystals" will be entirely adequate. Resonators are (usually) cheaper and can eliminate 2 external capacitors. Murata have had good feedback on this list as being responsive to customer needs and understanding specific microprocessor oscillator circuit demands. What about higher accuracies? What is >the maximum (practical) achievable accuracy (i.e. in production, not like 1 >in a 1000 will get it) for various High speed clocks? What about driving >multiple PICs at reliable high speed, anything good for this (be nice not to >have to redesign the circuit when another PIC (and hence load >resistance\capacitance\inductance) are added? You should be able to get essentially 100% compliance at this (low) accuracy requirement. What do you mean by "high speed" Changes in crystal parameters can make a particular capacitor/microprocessor combination suddenly not work. However, any crystal manufacturer worth their salt will be able to guarantee to meet a prior spec given a sample and circuit description. Try Rakon for starters. AFAIK they were originally a NZ based firm but they now supply some very smart crystal based products worldwide to some very large users. There are many many more reputable suppliers. Russell McMahon _____________________________ >From another world - www.easttimor.com What can one man* do? Help the hungry at no cost to yourself! at http://www.thehungersite.com/ (* - or woman, child or internet enabled intelligent entity :-)) -----Original Message----- From: Thomas Brandon To: PICLIST@MITVMA.MIT.EDU Date: Wednesday, 13 October 1999 12:58 Subject: Clock Accuracy >Thanks, >Tom. >