Datasheet

47
8493A–AVR–02/12
XMEGA C4
26. ADC – 12-bit Analog to Digital Converter
26.1 Features
• One Analog to Digital Converter (ADC)
• 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
– 16 single-ended inputs
– 16x4 differential inputs without gain
– 8x4 differential input with gain
• Built-in differential gain stage
–
1/2x, 1x, 2x, 4x, 8x, 16x, 32x, and 64x gain options
• Single, continuous and scan conversion options
• Three internal inputs
– Internal temperature sensor
–V
CC
voltage divided by 10
– 1.1V bandgap voltage
• Internal and external reference options
• Compare function for accurate monitoring of user defined thresholds
• Optional event triggered conversion for accurate timing
• Optional interrupt/event on compare result
26.2 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.
Both internal and external reference voltages can be used. An integrated temperature sensor is
available for use with the ADC. The V
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 mini-
mum software intervention required.