AT32UC3B0512-A2UES ATMEL [ATMEL Corporation], AT32UC3B0512-A2UES Datasheet - Page 14

• Manufacturer Part Number: AT32UC3B0512-A2UES
• Description: 32-bit AVR Microcontroller
• Manufacturer: ATMEL [ATMEL Corporation]

5.2
5.3
5.4
5.5
5.6
5.6.1
RESET_N pin
TWI pins
GPIO pins
High drive pins
Power Considerations
Power Supplies
The RESET_N pin is a schmitt input and integrates a permanent pull-up resistor to VDDIO. As
the product integrates a power-on reset cell, the RESET_N pin can be left unconnected in case
no reset from the system needs to be applied to the product.
When these pins are used for TWI, the pins are open-drain outputs with slew-rate limitation and
inputs with inputs with spike-filtering. When used as GPIO-pins or used for other peripherals, the
pins have the same characteristics as GPIO pins.
All the I/O lines integrate a pull-up resistor. Programming of this pull-up resistor is performed
independently for each I/O line through the GPIO Controllers. After reset, I/O lines default as
inputs with pull-up resistors disabled, except when indicated otherwise in the column “Reset
Value” of the GPIO Controller user interface table.
The four pins PA20, PA21, PA22, PA23 have high drive output capabilities.
The AT32UC3B has several types of power supply pins:
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The ground pins GND are common to VDDCORE, VDDIO and VDDPLL. The ground pin for
VDDANA is GNDANA.
For QFN packages, the center pad must be left unconnected.
Refer to “Electrical Characteristics” on page 35 for power consumption on the various supply
pins.
The main requirement for power supplies connection is to respect a star topology for all electrical
connection.
VDDIO: Powers I/O lines. Voltage is 3.3V nominal.
VDDANA: Powers the ADC Voltage is 3.3V nominal.
VDDIN: Input voltage for the voltage regulator. Voltage is 3.3V nominal.
VDDCORE: Powers the core, memories, and peripherals. Voltage is 1.8V nominal.
VDDPLL: Powers the PLL. Voltage is 1.8V nominal.