ATMega chip full datasheet - UCSD Department of Physics

ATmega48A/PA/88A/PA/168A/PA/328/P30.6.3 ATmega168PA 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 30-11.PRR bitATmega168PA: 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 2.86uA 20.3uA 52.2uAPRTWI 6.00uA 44.1uA 122.0uAPRTIM2 4.97uA 33.2uA 79.8uAPRTIM1 3.50uA 23.0uA 55.3uAPRTIM0 1.43uA 9.2uA 21.4uAPRSPI 5.01uA 38.6uA 111.4uAPRADC 6.34uA 45.7uA 123.6uATable 30-12.PRR bitATmega168PA: Additional Current Consumption (percentage) in Active and IdlemodeAdditional Current consumptioncompared to Active with externalclock (see Figure 30-236 on page457 and Figure 30-237 on page458)PRUSART0 1.5% 8.9%PRTWI 3.2% 19.5%PRTIM2 2.4% 14.8%PRTIM1 1.7% 10.3%PRTIM0 0.7% 4.1%PRSPI 2.9% 17.1%PRADC 3.4% 20.3%Additional Current consumptioncompared to Idle with externalclock (see Figure 30-241 on page460 and Figure 30-242 on page460)It is possible to calculate the typical current consumption based on the numbers from Table 30-12 on page 463 for other V CC and frequency settings than listed in Table 30-11 on page 463.30.6.3.1 ExampleCalculate the expected current consumption in idle mode with TIMER1, ADC, and SPI enabledat V CC = 2.0V and F = 1MHz. From Table 30-12 on page 463, third column, we see that we needto add 10.3% for the TIMER1, 20.3% for the ADC, and 17.1% for the SPI module. Reading fromFigure 30-241 on page 460, 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 SPIenabled, gives:ICCtotal ≈0.027 mA ⋅ (1 + 0.103 + 0.203 + 0.171) ≈0.040mA8271D–AVR–05/11463