ATxmega32A4 Atmel Corporation, ATxmega32A4 Datasheet - Page 41

• Manufacturer Part Number: ATxmega32A4
• Manufacturer: Atmel Corporation

Specifications of ATxmega32A4

• Flash (kbytes): 32 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 34
• Ext Interrupts: 34
• Usb Speed: No
• Usb Interface: No
• Spi: 7
• Twi (i2c): 2
• Uart: 5
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 12
• Adc Resolution (bits): 12
• Adc Speed (ksps): 2000
• Analog Comparators: 2
• Resistive Touch Screen: No
• Dac Channels: 2
• Dac Resolution (bits): 12
• Temp. Sensor: Yes
• Crypto Engine: AES/DES
• Sram (kbytes): 4
• Eeprom (bytes): 1024
• 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: 5
• Output Compare Channels: 16
• Input Capture Channels: 16
• Pwm Channels: 16
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

25. ADC - 12-bit Analog to Digital Converter
25.1
25.2
8069Q–AVR–12/10
Features
Overview
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XMEGA A4 devices have one Analog to Digital Converter (ADC), see
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 limitations on samples speed versus 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. An accurate internal 1.0V
reference is available.
An integrated temperature sensor is available and the output from this can be measured with the
ADC. The output from the DAC, VCC/10 and the Bandgap voltage can also be measured by the
ADC.
One ADC with 12-bit resolution
2 Msps sample rate
Signed and Unsigned conversions
4 result registers with individual input channel control
12 single ended inputs
8x4 differential inputs
4 internal inputs:
Software selectable gain of 2, 4, 8, 16, 32 or 64
Selectable accuracy of 8- or 12-bit.
Internal or External Reference selection
Event triggered conversion for accurate timing
DMA transfer of conversion results
Interrupt/Event on compare result
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Integrated Temperature Sensor
DAC Output
VCC voltage divided by 10
Bandgap voltage
Figure 25-1 on page
XMEGA A4
42.
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