I was just reading the tutorial
https://learn.sparkfun.com/tutorials/how-to-power-a-project
when I came across the figure of 20mA stated as the current draw of the ATMega328 under normal conditions. How was this figure obtained? Thanks in advance.
Probably from the datasheet…
[EDIT] jremington is right though, I didn’t account for the regulator.
The figure of 20 mA is not correct in general. http://gammon.com.au/power
jiphre:
… I came across the figure of 20mA stated as the current draw of the ATMega328 under normal conditions. How was this figure obtained?
That figure was probably arrived at by emperical measurement of whatever board they were using. It sounds like a good ballpark for a processor of this ilk that isn’t in some power saving mode. Power saving modes can lower that figure significantly. Remember, there are likely other components on whatever board you may be using that contribute to the total power consumption of the board (regulators, other digital/analog parts, LEDs, etc). Also, processor speed will affect current draw.