Datasheet

 2018 Microchip Technology Inc. Data Sheet Complete DS40002059A-page 57
ATxmega32E5/16E5/8E5
28. ADC – 12-bit Analog to Digital Converter
28.1 Features
 12-bit resolution
 Up to 300 thousand samples per second
 Down to 2.3μs conversion time with 8-bit resolution
 Down to 3.35μs conversion time with 12-bit resolution
 Differential and single-ended input
 Up to 16 single-ended inputs
 16x8 differential inputs with optional gain
 Built-in differential gain stage
 1/2x, 1x, 2x, 4x, 8x, 16x, 32x, and 64x gain options
 Single, continuous and scan conversion options
 Four internal inputs
 Internal temperature sensor
 DAC output
 AV
CC
voltage divided by 10
 1.1V bandgap voltage
 Internal and external reference options
 Compare function for accurate monitoring of user defined thresholds
 Offset and gain correction
 Averaging
 Over-sampling and decimation
 Optional event triggered conversion for accurate timing
 Optional interrupt/event on compare result
 Optional EDMA transfer of conversion results
28.2 Overview
The ADC converts analog signals to digital values. The ADC has 12-bit resolution and is capable of converting up to 300
thousand samples per second (ksps). 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.
The ADC measurements can either be started by application software or an incoming event from another peripheral in the
device. The ADC measurements can be started with predictable timing, and without software intervention. It is possible to
use EDMA 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, AV
CC
/10, and the bandgap voltage can also be measured by the ADC.
The ADC has a compare function for accurate monitoring of user defined thresholds with minimum software intervention
required.
When operation in noisy conditions, the average feature can be enabled to increase the ADC resolution. Up to 1024 sam-
ples can be averaged, enabling up to 16-bit resolution results. In the same way, using the over-sampling and decimation
mode, the ADC resolution is increased up to 16-bits, which results in up to 4-bit extra lsb resolution. The ADC includes var-
ious calibration options. In addition to standard production calibration, the user can enable the offset and gain correction to
improve the absolute ADC accuracy.