7.3 Power Supply Modes

The PIC32CX-BZ2 supports a single power supply from 1.9V to 3.6V. The IO supply cannot be decoupled from the main supply. The same voltage must be applied to VDDx, PMU_VDDIO, VPMU_VDDC and AVDD with different levels of filtering. The internal voltage regulator has the following four different modes:

• Linear mode – This mode does not require any external inductor. This is the default mode when the CPU and peripherals are running. In this mode, the SoC is powered through the MLDO.
• Switching mode (Buck) – This is the most efficient mode when the CPU and peripherals are running. In this mode, the SoC is powered by the DC-DC converter.
• Low Power (PSK) mode – This is the mode used when the device is in Standby mode.
• Shutdown mode – When the device is in Backup mode, the internal regulator is turned off.

Selecting between the Switching mode and Linear mode can be done by software on-the-fly, but the power supply must be designed according to which mode is to be used.