ATMega chip full datasheet - UCSD Department of Physics

ATmega48A/PA/88A/PA/168A/PA/328/P30.4.3 ATmega88PA: Supply Current of IO ModulesThe tables and formulas below can be used to calculate the additional current consumption forthe different I/O modules in Active and Idle mode. The enabling or disabling of the I/O modulesare controlled by the Power Reduction Register. See ”Power Reduction Register” on page 43 fordetails.Table 30-7.PRR bitATmega88PA: Additional Current Consumption for the different I/O modules(absolute values)Typical numbersV CC = 2V, F = 1MHz V CC = 3V, F = 4MHz V CC = 5V, F = 8MHzPRUSART0 3.0uA 21.3uA 97.9uAPRTWI 6.1uA 45.4uA 219.0uAPRTIM2 5.2uA 35.2uA 149.5uAPRTIM1 3.8uA 25.6uA 110.0uAPRTIM0 1.5uA 9.8uA 39.6uAPRSPI 5.2uA 40.0uA 199.6uAPRADC 6.3uA 48.7uA 247.0uATable 30-8.PRR bitATmega88PA: Additional Current Consumption (percentage) in Active and IdlemodeAdditional Current consumptioncompared to Active with externalclock (see Figure 30-142 on page407 and Figure 30-143 on page408)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%Additional Current consumptioncompared to Idle with externalclock (see Figure 30-147 on page410 and Figure 30-148 on page410)It is possible to calculate the typical current consumption based on the numbers from Table 30-8for other V CC and frequency settings than listed in Table 30-7.30.4.3.1 ExampleCalculate the expected current consumption in idle mode with TIMER1, ADC, and SPI enabledat V CC = 2.0V and F = 1MHz. From Table 30-8, 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 30-147on page 410, 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:ICCtotal ≈0.027 mA ⋅ (1 + 0.136 + 0.263 + 0.215) ≈0.043mA8271D–AVR–05/11413