Datasheet

PRR bit Additional Current consumption
compared to Active with external clock
(See Figure 30-1 and Figure 30-2)
Additional Current consumption
compared to Idle with external clock (See
Figure 30-6 and Figure 30-7)
PRTIM2 3.3% 16.3%
PRTIM1 1.9% 9.1%
PRTIM0 0.9% 4.3%
PRADC 3.65% 17.9%
PRSPI 2.5% 12.4%
It is possible to calculate the typical current consumption based on the numbers from Table 30-2 for other
V
CC
and frequency settings than listed in Table 30-1.
Calculate the expected current consumption in idle mode with TIMER1, ADC, and SPI
enabled at V
CC
= 2.0V and F = 1MHz. From Table 30-2, third column, we see that we
need to add 9.1% for the TIMER1, 17.9% for the ADC, and 12.4% for the SPI module.
Reading from Figure 30-6, we find that the idle current consumption is ~0.078 mA at V
CC
= 2.0V and F = 1MHz. The total current consumption in idle mode with TIMER1, ADC,
and SPI enabled, gives:


 0.078  1 + 0.091 + 0.179 + 0.124  0.109
30.4. Power-down Supply Current
Figure 30-11. Power-down Supply Current vs. V
CC
(Watchdog Timer Disabled)
0
0.5
1
1.5
2
2.5
1.5 2 2.5 3 3.5 4 4.5 5 5.5
V
CC
(V)
I
CC
(uA)
85
o
C
25
o
C
-40
o
C
Atmel ATmega644A [DATASHEET]
Atmel-42716C-ATmega644A_Datasheet_Complete-10/2016
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