Datasheet
33. ADC – Analog-to-Digital Converter
33.1 Overview
The Analog-to-Digital Converter (ADC) converts analog signals to digital values. The ADC has 12-bit
resolution, and is capable of converting up to 350ksps. The input selection is flexible, and both differential
and single-ended measurements can be performed. 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.
ADC measurements can be started by either application software or an incoming event from another
peripheral in the device. 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 bandgap voltage as well as the
scaled I/O and core voltages 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.
The ADC may be configured for 8-, 10- or 12-bit results, reducing the conversion time. ADC conversion
results are provided left- or right-adjusted, which eases calculation when the result is represented as a
signed value. It is possible to use DMA to move ADC results directly to memory or peripherals when
conversions are done.
33.2 Features
• 8-, 10- or 12-bit resolution
• Up to 350,000 samples per second (350ksps)
• Differential and single-ended inputs
– Up to 32 analog input
– 25 positive and 10 negative, including internal and external
• Five internal inputs
– Bandgap
– Temperature sensor
– DAC
– Scaled core supply
– Scaled I/O supply
• 1/2x to 16x gain
• Single, continuous and pin-scan conversion options
• Windowing monitor with selectable channel
• Conversion range:
– V
ref
[1v to V
DDANA
- 0.6V]
– ADCx * GAIN [0V to -V
ref
]
• Built-in internal reference and external reference options
SAM D21 Family
ADC – Analog-to-Digital Converter
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40001882D-page 891