ATmega8 at 3.0V can use 8MHz internal oscillator?

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#1
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I have an ATmega8 that I want to run at 3.0V (but 3.3V is ok).

I don't want an external oscillator, only internal oscillator, and I want it running at either 7.3728 MHz or 8MHz. I prefer 7.3728 MHz because it has zero error rate for UART. But 8MHz is ok, as the internal oscillator can only do at best 4MHz or 8MHz.

But on the ATmega datasheet, Figure 171 on page 276, it appears to say that I need at least 5V to get 8MHz.

What would happen if I give it just 3.0V? Would it really just give me ~7.2MHz? Will I get about 7.3728 MHz if I gave it 3.3V?

How do YOU make a robot?
http://www.societyofrobots.com

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It would give you 8MHz, you would run the chip outside of it's spec (overclocked by 100%)

/Martin.

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Ever thought of switching to mega88? - better in almost every way. (apart from anything else you can also debugWire it with a Dragon)

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Hmmm the ATmega168 appears to do 8MHz at 3.3V . . . I guess I'll go with that option . . .

Thanks mtaschl, didn't occur to me to look at the other pin compatible ATmegas . . .

How do YOU make a robot?
http://www.societyofrobots.com