ATxmega256A3U Atmel Corporation, ATxmega256A3U Datasheet - Page 45

• Manufacturer Part Number: ATxmega256A3U
• Manufacturer: Atmel Corporation

Specifications of ATxmega256A3U

• Flash (kbytes): 256 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 50
• Ext Interrupts: 50
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 10
• Twi (i2c): 2
• Uart: 7
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 16
• Adc Resolution (bits): 12
• Adc Speed (ksps): 2000
• Analog Comparators: 4
• Resistive Touch Screen: No
• Dac Channels: 2
• Dac Resolution (bits): 12
• Temp. Sensor: Yes
• Crypto Engine: AES/DES
• Sram (kbytes): 16
• Eeprom (bytes): 4096
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.6 to 3.6
• Operating Voltage (vcc): 1.6 to 3.6
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 7
• Output Compare Channels: 22
• Input Capture Channels: 22
• Pwm Channels: 22
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

27. ADC - 12-bit Analog to Digital Converter
27.1
27.2
8386A–AVR–07/11
Features
Overview
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There are two Analog to Digital Converters (ADCs) modules that can be operated simultane-
ously, individually or synchronized.
The ADC converts analog signals to digital values. The ADC has 12-bit resolution and is capable
of converting up to 2Million Samples Per Second (MSPS). The input selection is flexible, and
both single-ended and differential measurements can be done. For differential measurements
an optional gain stage is available to increase the dynamic range. In addition several internal
signal inputs are available. The ADC can provide both signed and unsigned results.
This is a pipelined ADC that consists of several consecutive stages. The pipelined design allows
high sample rate at a low System Clock frequency. It also means that a new input can be sam-
pled and a new ADC conversion started while other ADC conversions are still ongoing. This
remove dependencies between sample rate and propagation delay.
The ADC has four conversion channels (Channel 0-3) with individual input selection, result reg-
isters and conversion start control. The ADC can then keep and use four parallel configurations
and results, and this will ease use for applications with high data throughput or multiple modules
using the ADC independently. It is possible to use DMA to move ADC results directly to memory
or peripherals when conversions are done.
Both internal and external reference voltages can be used. An integrated temperature sensor is
available for use with the ADC. The output from the DAC, VCC/10 and the Bandgap voltage can
also be measured by the ADC.
Two Analog to Digital Converters
12-bit resolution
Up to 2 Million Samples Per Second
Differential and Single-ended input
Built in differential gain stage
Single, continues and scan conversion options
4 internal inputs
4 conversion channels with individual input control and result registers
Internal and external reference options
Compare function for accurate monitoring of user defined thresholds
Optional event triggered conversion for accurate timing
Optional DMA transfer of conversion results
Optional interrupt/event on compare result
– 4 inputs can be sampled within 1.5µs
– Down to 2.5µs conversion time with 8-bit resolution
– Down to 3.5µs conversion time with 12-bit resolution
– Up to 16 single-ended inputs
– 16x4 differential inputs without gain
– 16x4 differential input with gain
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– Internal Temperature sensor
– DAC Output
– VCC voltage divided by 10
– 1.1V Bandgap voltage
– Enable 4 parallel configurations and results
1/2
x, 1x, 2x, 4x, 8x, 16x, 32x and 64x gain options
XMEGA A3U
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