Author Topic: Crystal for the ATmega168  (Read 5832 times)

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Offline MarkBrownTopic starter

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Crystal for the ATmega168
« on: August 20, 2008, 10:35:43 PM »
I have seen in the tutorials that a frequency crystal can be added to increase the speed of the ATmega168.  Also, the UART tutorial says it is needed for faster speeds.  Unfortunately, I am unable to find a part number for one, and there are so many different types and sizes available on the internet.  Is anyone able to provide me with a name, part number, or something else that can help me find it?

Mark
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Offline pomprocker

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Re: Crystal for the ATmega168
« Reply #1 on: August 21, 2008, 12:35:00 AM »
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Offline emmannuel

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Re: Crystal for the ATmega168
« Reply #2 on: August 21, 2008, 02:03:13 AM »
Under the USART section of the datasheet it mentions what crystal speeds you want to use to achieve your desired baud rate.

I believe under the clock section it mentions how to set it up and what size capacitors to use with it.

The HC49/US is the best (simplest/smallest) package/size I've used.
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Offline Admin

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Re: Crystal for the ATmega168
« Reply #3 on: August 22, 2008, 10:38:00 PM »
Often the crystal datasheet will tell you what capacitors to use. If you want, just look at my Axon schematic and copy the crystal part.
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Offline pomprocker

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Re: Crystal for the ATmega168
« Reply #4 on: October 14, 2008, 12:00:00 PM »
hmm, above I linked to a 20MHz crystal, but in the data sheet I thought I read max is 16MHz. Can someone explain a little better? There seems to be many types of clock sources an ATmega168 can use.
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Offline Steel_monkey

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Re: Crystal for the ATmega168
« Reply #5 on: October 14, 2008, 01:23:47 PM »
There are many sources, but most of them are useless  ;D , like ceramic resonators.
Atmel guaranty ATmega 168 to work properly on 16 MHz clock maximum. In reality, it can be speed up to 20 MHz without problems, but it is totally on your own risk.
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