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SOT: Why, oh why? Oscillators
Posted: Wed Aug 10, 2022 10:39 pm
by BillO
IS going from 50MHz to 100MHz crossing some sort of hard physical line (not that I know of, BTW).
I wanted to source a 100MHz can oscillator as a (sorta) high frequency standard, but the cheapest one I could find was $127!!! A 50MHz oscillator from the same source was 1/33 the price.
That seems like a pretty steep step.
Re: SOT: Why, oh why? Oscillators
Posted: Wed Aug 10, 2022 11:26 pm
by GARTHWILSON
Let us know if you find a good PLL solution. I suppose the trouble with PLLs is that the computer would have to write to it to set the frequency; but if it's not running yet, how can it, unless there's a really low-frequency default at which the computer is guaranteed to be able to run before it kicks the frequency up near its maximum dependable limit.
Re: SOT: Why, oh why? Oscillators
Posted: Thu Aug 11, 2022 12:46 am
by BillO
Actually, I was just looking for stand alone 5V oscillator in a can. They do have them, they just cost a lot. Digikey have them listed to over $3000. Their cheapest is $127.
Re: SOT: Why, oh why? Oscillators
Posted: Thu Aug 11, 2022 1:13 am
by jds
It might be because you need 5v, by the time a lot of electronics got over 50 MHz they were mostly running at 3.3v. Some 5v systems that did need a fast clock used a PLL to multiply a 25 or 33 MHz input, for example the MC88915.
Re: SOT: Why, oh why? Oscillators
Posted: Thu Aug 11, 2022 1:58 am
by CountChocula
I have a few spares that I bought from China a while back (they were
suspiciously inexpensive, but they seem to perform to spec, at least to the extent that my 'scope can validate).
I don't know if I just got lucky, but I'm happy to drop one in the mail if you pm me your address.
Re: SOT: Why, oh why? Oscillators
Posted: Thu Aug 11, 2022 4:45 am
by Dr Jefyll
Actually, I was just looking for stand alone 5V oscillator in a can.
Perhaps it's the "in a can" aspect that's problematic. At any rate, I had no difficult with price or availability in 2015 when I selected an 80 MHz oscillator in SMD format. (And it's 5V powered.)
I hacked my own mounting, as this was for a through-hole project (wire wrap, in fact) with very little available space.
-- Jeff
Re: SOT: Why, oh why? Oscillators
Posted: Thu Aug 11, 2022 3:44 pm
by BillO
I have a few spares that I bought from China a while back (they were
suspiciously inexpensive, but they seem to perform to spec, at least to the extent that my 'scope can validate).
I don't know if I just got lucky, but I'm happy to drop one in the mail if you pm me your address.
PM sent. Thanks Count!
Re: SOT: Why, oh why? Oscillators
Posted: Thu Aug 11, 2022 3:45 pm
by BillO
Perhaps it's the "in a can" aspect that's problematic. At any rate, I had no difficult with price or availability in 2015 when I selected an 80 MHz oscillator in SMD format. (And it's 5V powered.)
I hacked my own mounting, as this was for a through-hole project (wire wrap, in fact) with very little available space.
That's another possibility I could look into.