31.2 Overview

The Analog-to-Digital Converter (ADC) peripheral is a single-ended ADC with a 10-bit resolution. It is connected to an analog input multiplexer, which allows selection between multiple inputs. The ADC measures the voltage between the selected input and 0V (GND). The ADC inputs can be internal (for example, the internal temperature sensor) 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, which 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 window compare feature is available to monitor the input signal. It can be configured to trigger an interrupt if the sample is either below or above a user-defined threshold, or inside or outside a user-defined window.

The ADC input signal is fed through a sample-and-hold circuit, which ensures that the input voltage to the ADC is kept at a constant level during 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 through the external analog reference pin (EXTVREF).