Datasheet

303
ATmega325/3250/645/6450
2570K–AVR–04/07
Figure 143. Idle Supply Current vs. V
CC
(32 kHz External Oscillator)
Supply Current of I/O modules The tables and formulas below can be used to calculate the additional current consump-
tion for the different I/O modules in Active and Idle mode. The enabling or disabling of
the I/O modules are controlled by the Power Reduction Register. See “PRR – Power
Reduction Register” on page 37 for details.
It is possible to calculate the typical current consumption based on the numbers from
Table 128 for other V
CC
and frequency settings than listed in Table 127.
IDLE SUPPLY CURRENT vs. V
CC
32kHz EXTERNAL OSCILLATOR
85 ˚C
25 ˚C
-40 ˚C
0
5
10
15
20
25
30
35
1.5 2 2.5 3 3.5 4 4.5 5 5.5
V
CC
(V)
I
CC
(uA)
Table 127.
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
PRADC 17 µA 116 µA 562 µA
PRUSART0 9 µA 59 µA 248 µA
PRSPI 10 µA 62 µA 257 µA
PRTIM1 5 µA 33 µA 135 µA
Table 128.
Additional Current Consumption (percentage) in Active and Idle mode
PRR bit
Additional Current consumption
compared to Active with external
clock
(see Figure 134 and Figure 135)
Additional Current consumption
compared to Idle with external
clock
(see Figure 139 and Figure 140)
PRADC 5.4% 16.8%
PRUSART0 2.7% 8.5%
PRSPI 2.9% 9.0%
PRTIM1 1.5% 4.8%