PIC16F631/677/685/687/689/690
8.0
COMPARATOR MODULE
FIGURE 8-1:
V
IN
+
V
IN
-
SINGLE COMPARATOR
+
–
Output
Comparators are used to interface analog circuits to a
digital circuit by comparing two analog voltages and
providing a digital indication of their relative magnitudes.
The comparators are very useful mixed signal building
blocks because they provide analog functionality
independent of program execution. The Analog
Comparator module includes the following features:
•
•
•
•
•
•
•
•
•
•
•
Independent comparator control
Programmable input selection
Comparator output is available internally/externally
Programmable output polarity
Interrupt-on-change
Wake-up from Sleep
PWM shutdown
Timer1 gate (count enable)
Output synchronization to Timer1 clock input
SR Latch
Programmable and fixed voltage reference
Note:
Only Comparator C2 can be linked to
Timer1.
V
IN
-
V
IN
+
Output
Note:
The black areas of the output of the
comparator represents the uncertainty
due to input offsets and response time.
8.1
Comparator Overview
A single comparator is shown in Figure 8-1 along with
the relationship between the analog input levels and
the digital output. When the analog voltage at V
IN
+ is
less than the analog voltage at V
IN
-, the output of the
comparator is a digital low level. When the analog
voltage at V
IN
+ is greater than the analog voltage at
V
IN
-, the output of the comparator is a digital high level.
©
2007 Microchip Technology Inc.
DS41262D-page 93
MICROCHIP [ MICROCHIP TECHNOLOGY ]
