60.2 Power Supply

The SAM D5x/E5x supports a single or dual power supply from 1.71V to 3.63V. The same voltage must be applied to both VDDIO and VDDANA. VDDIOB level must be lower or equal to VDDIO / VDDANA.

When I/O pads in the VDDIOB cluster are multiplexed as analog pads, VDDANA is used to power the I/O. Using this configuration may result in an electrical conflict if the VDDIOB voltage is different from that of VDDIO / VDDANA. If the application has such requirements, it is required to power VDDIOB, VDDIO, and VDDANA from the same supply source to ensure that they are always at the same voltage.

The internal voltage regulator has four different modes:

• Linear mode: This mode does not require any external inductor. This is the default mode when CPU and peripherals are running
• Switching mode (Buck): The most efficient mode when the CPU and peripherals are running.
• Low Power (LP) mode: This is the default 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 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.