ATXMEGA128A4_09 Datasheet, PDF (46/104 Pages) ATMEL Corporation – 8/16-bit XMEGA A4 Microcontroller

XMEGA A4
27.3 Input Selection
27.4
The Analog comparators have a very flexible input selection and the two comparators grouped
in a pair may be used to realize a window function. One pair of analog comparators is shown in
Figure 27-1 on page 45.
• Input selection from pin
– Pin 0, 1, 2, 3, 4, 5, 6 selectable to positive input of analog comparator
– Pin 0, 1, 3, 5, 7 selectable to negative input of analog comparator
• Internal signals available on positive analog comparator inputs
– Output from 12-bit DAC
• Internal signals available on negative analog comparator inputs
– 64-level scaler of the VCC, available on negative analog comparator input
– Bandgap voltage reference
– Output from 12-bit DAC
Window Function
The window function is realized by connecting the external inputs of the two analog comparators
in a pair as shown in Figure 27-2.
Figure 27-2. Analog comparator window function
Upper limit of window
+
AC0
-
Input signal
+
AC1
Lower limit of window _-
Interrupt
sensitivity
control
Interrupts
Events
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8069L–AVR–11/09