In Chapter 3, a great deal of information was presented concerning the internal workings of the Atmel AVR chip. Here you look at the AVR as just another (if complex) electronic component.
Both the ATmega328 and the ATmega2560 share an absolute maximum supply voltage of 6.0V. Operation at or even near the absolute maximum value “may affect device reliability,” according to the Atmel datasheet. The normal voltage range for both parts is 1.8V to 5.5V. Note that lower voltages reduce the maximum possible clock speed.
The power requirements of the AVR depend mostly on the operating frequency of the CPU. The higher the frequency, the higher the current consumption. At 16MHz, the ATmega328 draws just under 10mA (0.010A) ...