Datasheet

16
32059L–AVR32–01/2012
AT32UC3B
Refer to Section 9.3 on page 38 for decoupling capacitors values and regulator characteristics.
For decoupling recommendations for VDDIO, VDDANA, VDDCORE and VDDPLL, please refer
to the Schematic checklist.
5.6.2.2 Dual Power Supply
In case of dual power supply, VDDIN and VDDOUT should be connected to ground to prevent
from leakage current.
To avoid over consumption during the power up sequence, VDDIO and VDDCORE voltage dif-
ference needs to stay in the range given Figure 5-3.
Figure 5-3. VDDIO versus VDDCORE during power up sequence
5.6.3 Analog-to-Digital Converter (ADC) reference.
The ADC reference (ADVREF) must be provided from an external source. Two decoupling
capacitors must be used to insure proper decoupling.
Figure 5-4. ADVREF Decoupling
Refer to Section 9.4 on page 38 for decoupling capacitors values and electrical characteristics.
In case ADC is not used, the ADVREF pin should be connected to GND to avoid extra
consumption.
Extra consumption on VDDCORE
VDDCORE (V)
Extra consumption on VDDIO
VDDIO (V)
0 0.2 0.4 0.6 0.8 1 1.2 1.4
1.6
1.8 2
0
0.5
1.5
1
2
2.5
3
3.5
4
ADVREF
CC
VREF1VREF2
3.3V