AT32UC3A0128AU Atmel Corporation, AT32UC3A0128AU Datasheet - Page 18

• Manufacturer Part Number: AT32UC3A0128AU
• Manufacturer: Atmel Corporation

Specifications of AT32UC3A0128AU

• Flash (kbytes): 128 Kbytes
• Pin Count: 144
• Max. Operating Frequency: 66 MHz
• Cpu: 32-bit AVR
• # Of Touch Channels: 32
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 109
• Ext Interrupts: 109
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device + OTG
• Spi: 6
• Twi (i2c): 1
• Uart: 4
• Ssc: 1
• Ethernet: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 384
• Resistive Touch Screen: No
• Dac Channels: 2
• Dac Resolution (bits): 16
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 32
• Self Program Memory: YES
• External Bus Interface: 1
• Dram Memory: sdram
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 3.0-3.6 or (1.65-1.95+3.0-3.6)
• Operating Voltage (vcc): 3.0-3.6 or (1.65-1.95+3.0-3.6)
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 10
• Output Compare Channels: 16
• Input Capture Channels: 6
• Pwm Channels: 13
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

32058KS–AVR32–01/12
7.2
7.2.1
7.2.2
Voltage Regulator
Single Power Supply
Dual Power Supply
The AT32UC3A embeds a voltage regulator that converts from 3.3V to 1.8V. The regulator takes
its input voltage from VDDIN, and supplies the output voltage on VDDOUT. VDDOUT should be
externally connected to the 1.8V domains.
Adequate input supply decoupling is mandatory for VDDIN in order to improve startup stability
and reduce source voltage drop. Two input decoupling capacitors must be placed close to the
chip.
Adequate output supply decoupling is mandatory for VDDOUT to reduce ripple and avoid oscil-
lations. The best way to achieve this is to use two capacitors in parallel between VDDOUT and
GND as close to the chip as possible
Refer to
In case of dual power supply, VDDIN and VDDOUT should be connected to ground to prevent
from leakage current.
3.3V
1.8V
Section 12.3 on page 42
C
C
OUT2
IN2
for decoupling capacitors values and regulator characteristics
C
C
IN1
OUT1
VDDIN
VDDOUT
VDDIN
VDDOUT
Regulator
AT32UC3A
1.8V
18