Introduction

Microchip tinyAVR® 0- and 1-series, and megaAVR® 0-series devices feature a 10-bit successive approximation register (SAR) Analog-to-Digital Converter (ADC) and is capable of conversion rates up to 115 ksps. It features a flexible multiplexer, which allows the ADC to measure the voltage at multiple single-ended input pins. Single-ended input channels are referred to ground. The ADC input signal is fed through a Sample-and-Hold circuit which ensures that the input voltage to the ADC is held at a constant level during sampling. It also features multiple internal ADC reference voltages between 0.55V and V_DD.

An ADC conversion can be started by software, or by using the Event System (EVSYS) to route an event from other peripherals. A window compare feature is available for monitoring the input signal and can be configured to trigger an interrupt on user-defined thresholds for under, over, inside, or outside a window, with minimum software intervention required.

This application note describes the basic functionality of the ADC in Microchip tinyAVR® 0- and 1-series, and megaAVR® 0-series devices in Single-Ended mode. It contains code examples for Microchip devices to get started.