Data Sheet

403
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271H-AVR- ATmega-Datasheet_08/2014
31.4.3 ATmega88PA: Supply Current of IO 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 ”Power Reduction Register” on page 43 for details.
It is possible to calculate the typical current consumption based on the numbers from Table 31-8 for other V
CC
and frequency settings than listed in Table 31-7.
31.4.3.1 Example
Calculate the expected current consumption in idle mode with TIMER1, ADC, and SPI enabled at V
CC
= 2.0V
and F = 1MHz. From Table 31-8, third column, we see that we need to add 13.6% for the TIMER1, 26.3% for the
ADC, and 21.5% for the SPI module. Reading from Figure 31-147 on page 400, we find that the idle current
consumption is ~0.027 mA at V
CC
= 2.0V and F = 1MHz. The total current consumption in idle mode with
TIMER1, ADC, and SPI enabled, gives:
Table 31-7. ATmega88PA: 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
PRUSART0 3.0µA 21.3µA 97.9µA
PRTWI 6.1µA 45.4µA 219.0µA
PRTIM2 5.2µA 35.2µA 149.5µA
PRTIM1 3.8µA 25.6µA 110.0µA
PRTIM0 1.5µA 9.8µA 39.6µA
PRSPI 5.2µA 40.0µA 199.6µA
PRADC 6.3µA 48.7µA 247.0µA
Table 31-8. ATmega88PA: Additional Current Consumption (percentage) in Active and Idle mode
PRR bit
Additional Current consumption
compared to Active with external
clock (see Figure 31-142 on page
397 and Figure 31-143 on page
398)
Additional Current consumption
compared to Idle with external
clock (see Figure 31-147 on page
400 and Figure 31-148 on page
400)
PRUSART0 1.8% 11.4%
PRTWI 3.9% 24.4%
PRTIM2 2.9% 18.6%
PRTIM1 2.1% 13.6%
PRTIM0 0.8% 5.2%
PRSPI 3.5% 21.5%
PRADC 4.2% 26.3%
ICCtotal 0.027 mA (1 + 0.136 + 0.263 + 0.215) 0.043 mA