Datasheet

Table Of Contents
311
2570N–AVR–05/11
ATmega325/3250/645/6450
Figure 29-10. Idle Supply Current vs. V
CC
(32kHz External Oscillator)
29.3 Supply Current of I/O modules
The tables and formulas below can be used to calculate the additional current consumption 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 40 for details.
It is possible to calculate the typical current consumption based on the numbers from Table 29-2
for other V
CC
and frequency settings than listed in Table 29-1.
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 29-1. 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 17µA 116µA 562µA
PRUSART0 9µA 59µA 248µA
PRSPI 10µA 62µA 257µA
PRTIM1 5µA 33µA 135µA
Table 29-2. Additional Current Consumption (percentage) in Active and Idle mode
PRR bit
Additional Current consumption
compared to Active with external
clock
(see Figure 29-1 and Figure 29-2)
Additional Current consumption
compared to Idle with external
clock
(see Figure 29-6 and Figure 29-7)
PRADC 5.4% 16.8%
PRUSART0 2.7% 8.5%
PRSPI 2.9% 9.0%
PRTIM1 1.5% 4.8%