The internal circuitry is powered from 1.8 V. The 1.8-V LDO steps the voltage down from LDO_3V3 to 1.8 V. The 1.8-V LDO provides power to all internal low-voltage digital circuits which includes the digital core, memory, and other digital circuits. The 1.8-V LDO also provides power to all internal low-voltage analog circuits. See Table 10-1 for the recommended external capacitance on the LDO_1V8 pin.