Question on Crystal Oscillators (+ a thank you to Responders) - Page 1
Forum section: electronics / beginners

author: Andy-In_over_my_head
author_rank: Regular Contributor
timestamp: December 05, 2016, 12:04:21 am
content: I first want to thank the more experienced and knowledgeable for taking their time to come in the beginners forum to give us Noobs a boost when we need it... It's the genuine people that have pulled me hardest towards this expensive (to get started) hobby....I know for me, it's painful to get away from building and frying, rebuilding and retrying, and bread boarding my life away to get on my computer to type a bunch... but it's rad to have a place to bring my questions where they get quick answers!!ANYWAYS.. NOW THE QUESTION:Can crystal oscillators be combined is parallel or ... I guess series maybe.... Or some way to get a higher output MHz? (Maybe even torn apart and stack the crystal sheets? haha)For example, I happen to have many crystal oscillators, some of the very precise ones and some of the silver Twinkies.... I need to get a 16MHz output (Pretty easy to narrow down the suspects to just a few coming from a Noob) but I can only get close by combining 2...I mistakenly ordered from China... So those 50 will take a long time to arrive... So I reordered more a couple days ago and even though I get them tomorrow... This Is something I would like to know for the future...*If not, is there any controller that will be fast and precise enough? I have an NTE955M IC-TIMER/OSCILLATOR... Could that work for a stable enough reading for a micro-controller?*Thanks again... And like always...Input and criticism are always appreciated....I don't have thin skin (that doesn't mean to be a Rooster Sucker either)

author: Andy-In_over_my_head
author_rank: Regular Contributor
timestamp: December 05, 2016, 01:15:28 am
content: Quote from: evb149 on December 05, 2016, 12:41:47 amI'm going to have to read that a couple more times.. (I input things like this into my bluebeam program and have the program do "OCR" to recognize texts, then I google everything I don't understand, save it, then hyperlink all those words to the sheets I saved about them so I can bounce back and forth referencing... but I only take the time to do that for a brain explosion of information like this so I can learn it quicker)But I do understand a good amount of that....Basically I have a tube of micro-controllers that I want to load with whatever programming I find interesting...the ATMEGA328P-PU has a data sheet longer then I remember my entire Junior high Physical Science book being...I believe it needs the 16MHz Frequency to talk with my serial converter and computer... however there is an internal oscillator at 8MHz or so I believe.... But I am unsure if I can activate that function without first using a 16MHz...Now I'm no Arduino fanatic or Rasberry Pi fanatic... I just dropped a ton of money into them to have more to play with.. but because I like building my own things from nothing at all.... I just got some of the micro-controllers to build around them... not as a shortcut.. but more for a momentum conductor...Is there a way I can hook up my arbitrary/function waveform gen. to bypass this if ever needed?I honestly have not figured the whole oscilloscope/function/wave generator out yet... but I'm sure if I poke all those little buttons enough I could get it to output 16MHz and not the 25MHz it's default at...

author: ebclr
author_rank: Super Contributor
timestamp: December 05, 2016, 02:05:46 am
content: Take a look on this producthttp://www.cypress.com/documentation/datasheets/cy27410-4-pll-spread-spectrum-clock-generatorThis can generate a lot of high quality frequencies

author: AlfBaz
author_rank: Super Contributor
timestamp: December 05, 2016, 02:32:25 am
content: Sorry for the off topic but thanks for that ebclr. Just what I've been looking for

author: CatalinaWOW
author_rank: Super Contributor
timestamp: December 05, 2016, 02:39:52 am
content: All responders should pat themselves on the back. The best combination of thoroughness and accuracy I have seen on any forum.

author: danadak
author_rank: Super Contributor
timestamp: December 05, 2016, 11:50:47 am
content: If you are generating and prototyping a Mhz clock use scope and lookat CPU clock input pin. Tyically you will see a lot of ringing. Use a Rin series with clk gen to CPU clk in, experiment, 10 ohms to 100 ohmsto kill the ringing. Also pay attention to duty cycle. Most CPUs havelimited allowable DC range on their clk in, otherwise you can get somestrange behaviour in the CPU. Something like 45 - 55 % typical spec.Regards, Dana.