| Author: Qubo Hu, Microchip Inc. |
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 VDD.
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.