Datasheet

SAM3X / SAM3A [DATASHEET]
Atmel-11057C-ATARM-SAM3X-SAM3A-Datasheet_23-Mar-15
272
Figure 16-2. Separated Backup Supply Powering Scheme
Note: Restrictions: With Main Supply < 3V, some peripherals such as USB and ADC might not be operational. Refer to the
DC Characteristics of the product for actual possible ranges for such peripherals.
When a separated backup supply for VDDBU is not used (See Figure 16-3), since the external voltage applied on
VDDIO is kept, all of the I/O configurations (i.e. WKUP pin configuration) are kept during backup mode. When not
using backup batteries, VDDIORDY is set so the user does not need to program it.
VDDBU
VDDIN
Voltage
Regulator
VDDOUT
Main Supply (1.8V-3.6V)
VDDCORE
Backup Batteries
VDDIO
VDDANA
VDDUTMI
VDDPLL
FWUP
SHDN