Datasheet

Table Of Contents
54
XMEGA E5 [DATASHEET]
Atmel-8153J–AVR-ATxmega8E5-ATxmega16E5-ATxmega32E5_Datasheet–11/2014
30. AC – Analog Comparator
30.1 Features
Two Analog Comparators
Selectable propagation delay
Selectable hysteresis
No
Small
Large
Analog Comparator output available on pin
Flexible Input Selection
All pins on the port
Output from the DAC
Bandgap reference voltage
A 64-level programmable voltage scaler of the internal AVCC voltage
Interrupt and event generation on
Rising edge
Falling edge
Toggle
Window function interrupt and event generation on
Signal above window
Signal inside window
Signal below window
Constant current source with configurable output pin selection
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.