Datasheet

212
8018P–AVR–08/10
ATmega169P
21. AC - Analog Comparator
The Analog Comparator compares the input values on the positive pin AIN0 and negative pin
AIN1. When the voltage on the positive pin AIN0 is higher than the voltage on the negative pin
AIN1, the Analog Comparator output, ACO, is set. The comparator’s output can be set to trigger
the Timer/Counter1 Input Capture function. In addition, the comparator can trigger a separate
interrupt, exclusive to the Analog Comparator. The user can select Interrupt triggering on com-
parator output rise, fall or toggle. A block diagram of the comparator and its surrounding logic is
shown in Figure 21-1.
The Power Reduction ADC bit, PRADC, in ”PRR – Power Reduction Register” on page 45 must
be disabled by writing a logical zero to be able to use the ADC input MUX.
Figure 21-1. Analog Comparator Block Diagram
(2)
Notes: 1. See Table 21-1 on page 213.
2. Refer to Figure 1-1 on page 2 and Table 13-5 on page 74 for Analog Comparator pin
placement.
ACBG
BANDGAP
REFERENCE
ADC MULTIPLEXER
OUTPUT
ACME
ADEN
(1)