Datasheet

55XMEGA E5 [DATASHEET]

Atmel-8153H–AVR-ATxmega8E5-ATxmega16E5-ATxmega32E5_Datasheet–07/2014

30. AC – Analog Comparator

30.1 Features

z Two Analog Comparators

z Selectable propagation delay

z Selectable hysteresis

z No

z Small

z Large

z Analog Comparator output available on pin

z Flexible Input Selection

z All pins on the port

z Output from the DAC

z Bandgap reference voltage.

z A 64-level programmable voltage scaler of the internal AVCC voltage

z Interrupt and event generation on

z Rising edge

z Falling edge

z Toggle

z Window function interrupt and event generation on

z Signal above window

z Signal inside window

z Signal below window

z Constant current source with configurable output pin selection

z Source of asynchronous event

30.2 Overview

The Analog Comparator (AC) compares the voltage level on two inputs and gives a digital output based on this

comparison. The Analog Comparator may be configured to give interrupt requests and/or synchronous/asynchronous

events upon several different combinations of input change.

One important property of the Analog Comparator when it comes to the dynamic behavior, is the hysteresis. This

parameter may be adjusted in order to find the optimal operation for each application.

The input section includes analog port pins, several internal signals and a 64-level programmable voltage scaler. The

analog comparator output state can also be directly available on a pin for use by external devices. Using as pair they can

also be set in Window mode to monitor a signal compared to a voltage window instead of a voltage level.

A constant current source can be enabled and output on a selectable pin. This can be used to replace, for example,

external resistors used to charge capacitors in capacitive touch sensing applications.

The analog comparators are always grouped in pairs on each port. These are called analog comparator 0 (AC0) and

analog comparator 1 (AC1). They have identical behavior, but separate control registers. Used as pair, they can be set in

window mode to compare a signal to a voltage range instead of a voltage level.

PORTA has one AC pair. Notation is ACA.