Datasheet

SAM3X / SAM3A [DATASHEET]
Atmel-11057C-ATARM-SAM3X-SAM3A-Datasheet_23-Mar-15
20
5. Power Considerations
5.1 Power Supplies
The SAM3X/A series product has several types of power supply pins:
 VDDCORE pins: Power the core, the embedded memories and the peripherals; voltage ranges from 1.62V
to 1.95V.
 VDDIO pins: Power the peripherals I/O lines; voltage ranges from 1.62V to 3.6V.
 VDDIN pin: Powers the voltage regulator
 VDDOUT pin: Output of the voltage regulator
 VDDBU pin: Powers the Slow Clock oscillator and a part of the System Controller; voltage ranges from
1.62V to 3.6V. VDDBU must be supplied before or at the same time as VDDIO and VDDCORE.
 VDDPLL pin: Powers the PLL A, UPLL and 3–20 MHz Oscillator; voltage ranges from 1.62V to 1.95V.
 VDDUTMI pin: Powers the UTMI+ interface; voltage ranges from 3.0V to 3.6V, 3.3V nominal.
 VDDANA pin: Powers the ADC and DAC cells; voltage ranges from 2.0V to 3.6V.
Ground pins GND are common to VDDCORE and VDDIO pins power supplies.
Separated ground pins are provided for VDDBU, VDDPLL, VDDUTMI and VDDANA. These ground pins are
respectively GNDBU, GNDPLL, GNDUTMI and GNDANA.
5.2 Power-up Considerations
5.2.1 VDDIO Versus VDDCORE
V
DDIO
must always be higher than or equal to V
DDCORE
.
V
DDIO
must reach its minimum operating voltage (1.60 V) before V
DDCORE
has reached V
DDCORE(min)
. The minimum
slope for V
DDCORE
is defined by (V
DDCORE(min)
- V
T+
) / t
RST
.
If V
DDCORE
rises at the same time as V
DDIO
, the V
DDIO
rising slope must be higher than or equal to 5 V/ms.
If VDDCORE is powered by the internal regulator, all power-up considerations are met.