32.2 Overview

The Analog-to-Digital Converter (ADC) peripheral features a 10-bit single-ended ADC with 10-bit resolution. The ADC is connected to an analog input multiplexer for selection between multiple inputs. The ADC measures the voltage between the selected input and 0V (GND). The ADC inputs can be internal (for example, a voltage reference) or external analog input pins.

An ADC conversion can be started by software or by using the Event System (EVSYS) to route an event from other peripherals. This makes it possible to sample input signals periodically, trigger an ADC conversion on a particular condition, and trigger ADC conversions in Standby sleep mode. A digital window compare feature is available for monitoring the input signal. It can also be configured to trigger an interrupt if the sample is under or over a user-defined threshold or inside or outside a user-defined window, with minimum software intervention required.

The ADC input signal is fed through a sample-and-hold circuit that ensures that the input voltage to the ADC is kept at a constant level during the conversion.

The ADC supports sampling in bursts where a configurable number of samples are accumulated into a single ADC result (Sample Accumulation).

The ADC reference voltage can be either internal or supplied from the external analog reference pin (EXTVREF).