AVR Frequency vs. Current Consumption

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All,
Is there a curve somewhere that shows ocillator frequency vs. avr current consumption? I'm assuming for non-time critical applications, it is more efficient (power consumption wise) to run with a slower crystal.

Also, what is the slowest frequency for an AVR processor (8515 if it matters).

Thoughts?

Thank You,
Jon

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Fig 69 at the datasheet show the current.

If you can power down the most efficient is run fast, get the job done and then sleep

If you only can go idle then the most efficient is about 4 times faster than needed and idel 75% of the time.

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Hi Jon,

The AT90S8515 has fully static operation. This means it can operate down to 0Hz on external clock. However, if the internal oscillator is to be used, the minimum crystal frequency on the input is 455 KHz.

Best regards,

Morten, AVR tech. support, Atmel FAE

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Jon,
I was told that the 8515 needs at least 1MHz for programming. I was able to program at 921KHz but had problems somewhere below 800KHz.

Scott

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