ATXMEGA128B3-AU ATMEL [ATMEL Corporation], ATXMEGA128B3-AU Datasheet - Page 53

• Manufacturer Part Number: ATXMEGA128B3-AU
• Description: 8/16-bit Atmel XMEGA B3 Microcontroller
• Manufacturer: ATMEL [ATMEL Corporation]

30. AC – Analog Comparator
30.1
30.2
8074B–AVR–02/12
Features
Overview
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The analog comparator (AC) compares the voltage levels on two inputs and gives a digital out-
put based on this comparison. The analog comparator may be configured to generate interrupt
requests and/or events upon several different combinations of input change.
One important property of the analog comparator’s dynamic behavior is the hysteresis. This
parameter may be adjusted in order to achieve the optimal operation for each application.
The input selection includes analog port pins, several internal signals, and a 64-level program-
mable voltage scaler. The analog comparator output state can also be output on a pin for use by
external devices.
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.
PORTB has one AC pair. Notation is ACB.
Two Analog Comparators (AC)
Selectable hysteresis
Analog comparator output available on pin
Flexible input selection
Interrupt and event generation on:
Window function interrupt and event generation on:
Constant current source with configurable output pin selection
– No
– Small
– Large
– All pins on the port
– Bandgap reference voltage
– A 64-level programmable voltage scaler of the internal V
– Rising edge
– Falling edge
– Toggle
– Signal above window
– Signal inside window
– Signal below window
CC
voltage
XMEGA B3
53