5.1 Power Domains
Note: For the AVR® DBFamily of devices, AVDD is internally
connected to VDD (not separate power domains).
The AVR® DB family of devices has several power domains with the
following power supply pins:
| Domain | Pin | Description |
|---|---|---|
| VDD | VDD | Powers I/O lines, XOSCHF and the internal voltage regulator |
| AVDD | Powers I/O lines, XOSC32K (external 32.768 kHz oscillator) and the analog peripherals | |
| VDDIO2 | VDDIO2 | Powers I/O lines, optionally at a different voltage from VDD |
The same voltage must be applied to all VDD and AVDD pins. This common voltage is referred to as VDD in the data sheet.
The ground pins, GND, are common to VDD, AVDD and VDDIO2.
A subset of the device I/O pins can be powered by VDDIO2. This power domain is independent of VDD. Refer to the Multi-Voltage I/O section for further information.
For recommendations on layout and decoupling, refer to the Hardware Guidelines section.