Datasheet

45
8116J–AVR–06/2013
XMEGA A3B
Not recommended for new designs -
Use ATxmega256A3BU
27. AC - Analog Comparator
27.1 Features
• Four Analog Comparators
• Selectable Power vs. Speed
• Selectable hysteresis
– 0, 20 mV, 50 mV
• Analog Comparator output available on pin
• Flexible Input Selection
– All pins on the port
– Output from the DAC
– Bandgap reference voltage.
– Voltage scaler that can perform a 64-level scaling of the internal VCC 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
27.2 Overview
XMEGA A3B features four Analog Comparators (AC). An Analog Comparator compares two
voltages, and the output indicates which input is largest. The Analog Comparator may be config-
ured to give interrupt requests and/or events upon several different combinations of input
change.
Both hysteresis and propagation delays may be adjusted in order to find the optimal operation
for each application.
A wide range of input selection is available, both external pins and several internal signals can
be used.
The Analog Comparators are always grouped in pairs (AC0 and AC1) on each analog port. They
have identical behavior but separate control registers.
Optionally, the state of the comparator is directly available on a pin.
PORTA and PORTB each have one AC pair. Notations are ACA and ACB, respectively.