
407
ATmega165A/PA/325A/PA/3250A/PA/645A/P/6450A/P [DATASHEET]
8285E–AVR–02/2013
30.4.3
ATmega325PA: 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 Reduc-
It is possible to calculate the typical current consumption based on the numbers from
Table 30-8 for other V
CC and
30.4.3.1
Example 1
Calculate the expected current consumption in idle mode with USART0, TIMER1, and SPI enabled at V
CC = 3.0V
and F = 1MHz. From
Table 30-7, second column, we see that we need to add 13.1% for the USART0, 13.0% for
the SPI, and 13.2% for the TIMER1 module. Reading from
Figure 30-191, we find that the idle current consumption
is ~0.09 mA at V
CC = 3.0V and F = 1MHz. The total current consumption in idle mode with USART0, TIMER1, and
SPI enabled, gives:
Table 30-7.
ATmega325PA: Additional Current Consumption for the different I/O modules (absolute values)
PRR bit
Typical numbers
VCC = 2V, F = 1MHz
VCC = 3V, F = 4MHz
VCC = 5V, F = 8MHz
PRADC
7 A
44 A
195 A
PRUSART0
6.9 A
43.5 A
210 A
PRSPI
6.6 A
47 A
205 A
PRTIM1
7 A
47 A
206 A
Table 30-8.
ATmega325PA: 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
PRADC
3.2%
12.7%
PRUSART0
3.4%
13.1%
PRSPI
3.3%
13.0%
PRTIM1
3.4%
13.2%
ICCtotal
0.09mA
1
0.131
0.13
0.132
++
+
0.13mA