Datasheet

34. AC – Analog Comparators
34.1 Overview
The Analog Comparator (AC) supports multiple individual comparators. Each comparator (COMP)
compares the voltage levels on two inputs, and provides a digital output based on this comparison. Each
comparator may be configured to generate interrupt requests and/or peripheral events upon several
different combinations of input change.
Hysteresis can be adjusted to achieve the optimal operation for each application.
The input selection includes four shared analog port pins and several internal signals. Each comparator
output state can also be output on a pin for use by external devices.
The comparators are grouped in pairs on each port. The AC peripheral implements one or two pairs of
comparators . These are called Comparator 0 (COMP0) and Comparator 1 (COMP1) for the first pair and
Comparator 2 (COMP2) and Comparator 3 (COMP3) for the second pair. They have identical behaviors,
but separate control registers. Each pair can be set in window mode to compare a signal to a voltage
range instead of a single voltage level.
34.2 Features
• Up to Four individual comparators
• Analog comparator outputs available on pins
– Asynchronous or synchronous
• Flexible input selection:
– Four pins selectable for positive or negative inputs
– Ground (for zero crossing)
– Bandgap reference voltage
– 64-level programmable VDD scaler per comparator
– DAC (if available)
• Interrupt generation on:
– Rising or falling edge
– Toggle
– End of comparison
• Window function interrupt generation on:
– Signal above window
– Signal inside window
– Signal below window
– Signal outside window
• Event generation on:
– Comparator output
– Window function inside/outside window
• Optional digital filter on comparator output
SAM D21 Family
AC – Analog Comparators
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40001882D-page 930