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Relating clock crystal and 555 timer

And this may sound sttupid but can a 555 timer be used instead of a clock crystal/oscillator/resonator? If yes, then how? If no, then why? I'm asking this because I'm living in a place where a 555 is cheaper than the clock crystal...


Well bajdi told me that the 555 is incapable of producing that frequency (first man to do so). What I undersatand now is-

  1. The 555 is slow and suitable only for small frequencies in the order of a few kilohertz.
  2. The required capacitors and resistors are not available to use it at such high frequencies.

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You can technically use it but I don't think a 555 can oscilate as quickly as most crystals(16Mhz for example)

What microrocessor are you using? most recent microprocessors have a built in oscilator that can be used with no extra hardware.



I'm using ATMega 328PU but I was trying to find cheap options of giving it 16MHz clock instead of using it on 8MHz internal clock. The caps and resistors required for this (16MHz) is going to be hard to find...

I think you'll have trouble getting a 555 to operate in the MHz frequency range. 

I agree.