Datasheet

396
ATmega640/1280/1281/2560/2561
2549K–AVR–01/07
It is possible to calculate the typical current consumption based on the numbers from
Table 181 for other V
CC
and frequency settings than listed in Table 182.
Example 1 Calculate the expected current consumption in idle mode with USART0, TIMER1, and
TWI enabled at V
CC
= 2.0V and F = 1MHz. From Table 182 on page 396, third column,
we see that we need to add 17% for the USART0, 24% for the TWI, and 10% for the
TIMER1 module. Reading from Figure 172 on page 393, we find that the idle current
consumption is ~0,15mA at V
CC
= 2.0V and F = 1MHz. The total current consumption in
idle mode with USART0, TIMER1, and TWI enabled, gives:
PRTIM0 4.0 uA 24 uA 100 uA
PRSPI 15 uA 95 uA 400 uA
PRADC 12 uA 75 uA 315 uA
Table 182.
Additional Current Consumption (percentage) in Active and Idle mode
PRR bit
Additional Current consumption
compared to Active with external
clock
Additional Current consumption
compared to Idle with external
clock
PRUSART3 3.0% 17%
PRUSART2 3.0% 17%
PRUSART1 3.0% 17%
PRUSART0 3.0% 17%
PRTWI4.4% 24%
PRTIM5 1.8% 10%
PRTIM4 1.8% 10%
PRTIM3 1.8% 10%
PRTIM2 4.3% 23%
PRTIM1 1.8% 10%
PRTIM0 1.5% 8.0%
PRSPI 3.3% 18%
PRADC 4.5% 24%
Table 181.
Additional Current Consumption for the different I/O modules (absolute values)
PRR bit Typical numbers
V
CC
= 2V, F = 1MHz V
CC
= 3V, F = 4MHz V
CC
= 5V, F = 8MHz
ICCtotal 0,15mA 10,170,240,10+++()• 0,227mA≈≈