Datasheet

PRR bit Additional Current consumption
compared to Active with external clock
(see Figure 34-1 and Figure 34-2)
Additional Current consumption
compared to Idle with external clock (see
Figure 34-6 and Figure 34-7)
PRTIM0 0.8% 4.2%
PRSPI 3.3% 17.6%
PRADC 4.2% 22.1%
It is possible to calculate the typical current consumption based on the numbers from the above table for
other V
CC
and frequency settings.
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14.11.3 PRR
34.1.3.1 Example
Calculate the expected current consumption in Idle mode with TIMER1, ADC, and SPI enabled at V
CC
=
2.0V and F = 1 MHz. From the table Additional Current Consumption (percentage) in Active and Idle
mode in the previous section, third column, we see that we need to add 11.2% for the TIMER1, 22.1% for
the ADC, and 17.6% for the SPI module. Reading from the figure Idle Supply Current vs. Low Frequency
(0.1-1.0 MHz), we find that the idle current consumption is ~0.028mA at V
CC
= 2.0V and F = 1 MHz. The
total current consumption in Idle mode with TIMER1, ADC, and SPI enabled, gives:
I
CCtotal
 0.028mA(1+0.112+0.221+0.176)  0.042mA
34.1.4 Power-Down Supply Current
Figure 34-11. ATmega48A: Power-Down Supply Current vs. V
CC
(Watchdog Timer Disabled)
85 °C
25 °C
-40 °C
0
0.2
0.4
0.6
0.8
1
1.2
1.5 2 2.5 3 3.5 4 4.5 5 5.5
V
CC
(V)
I
CC
(uA)
ATmega48A/88A/168A
Typical Characteristics (TA = -40°C to 85°C)
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40002007A-page 401