ATxmega128A1 Atmel Corporation, ATxmega128A1 Datasheet - Page 289

• Manufacturer Part Number: ATxmega128A1
• Manufacturer: Atmel Corporation

Specifications of ATxmega128A1

• Flash (kbytes): 128 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 78
• Ext Interrupts: 78
• Usb Speed: No
• Usb Interface: No
• Spi: 12
• Twi (i2c): 4
• Uart: 8
• 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: 4
• Dac Resolution (bits): 12
• Temp. Sensor: Yes
• Crypto Engine: AES/DES
• Sram (kbytes): 8
• Eeprom (bytes): 2048
• Self Program Memory: YES
• External Bus Interface: 1
• Dram Memory: sdram
• 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: 8
• Output Compare Channels: 24
• Input Capture Channels: 24
• Pwm Channels: 24
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

25. ADC - Analog to Digital Converter
25.1
25.2
8077H–AVR–12/09
Features
Overview
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The ADC converts analog voltages to digital values. The ADC has 12-bit resolution and is capa-
ble of converting up to 2 million samples per second. 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 pipeline ADC. A pipeline ADC consists of several consecutive stages, where each
stage convert one part of the result. The pipeline design enables high sample rate at low clock
speeds, and remove dependencies between sample speed and propagation delay. This also
means that a new analog voltage can be sampled and a new ADC measurement started while
other ADC measurements are ongoing.
ADC measurements can either be started by application software or an incoming event from
another peripheral in the device. Four different result registers with individual input selection
(MUX selection) are provided to make it easier for the application to keep track of the data. Each
result register and MUX selection pair is referred to as an ADC Channel. It is possible to use
DMA to move ADC results directly to memory or peripherals when conversions are done.
Both internal and external analog reference voltages can be used. A very accurate internal
1.00V reference is available.
12-bit resolution
Up to 2 Msps sample and conversion rate
Single-ended or Differential measurements
Signed and Unsigned mode
4 result registers with individual input control
8 - 16 single-ended inputs
8x4 differential inputs without gain
8x4 differential input with gain
4 internal inputs
1x, 2x, 4x, 8x, 16x, 32x or 64x software selectable gain
4 inputs can be sampled within 1.5 µs
8-, or 12-bit selectable resolution
Minimum single result propagation delay of 2.5 µs (8-bit resolution)
Minimum single result propagation delay of 3.5 µs (12-bit resolution)
Built-in reference
Optional external reference
Optional event triggered conversion for accurate timing
Optional DMA transfer of conversion results
Optional interrupt/event on compare result
– Temperature Sensor
– DAC Output
– VCC voltage divided by 10
– Bandgap voltage
XMEGA A
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