PIC16F684T-I Datasheet, PDF (57/192 Pages) Microchip Technology – 14-Pin, Flash-Based 8-Bit CMOS Microcontrollers

8.0 COMPARATOR MODULE
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 the device program execution. The
analog Comparator module includes the following
features:
• Dual comparators
• Multiple comparator configurations
• Comparator outputs are available internally/
externally
• Programmable output polarity
• Interrupt-on-change
• Wake-up from Sleep
• Timer1 gate (count enable)
• Output synchronization to Timer1 clock input
• Programmable voltage reference
Note: Only Comparator C2 can be linked to
Timer1.
PIC16F684
8.1 Comparator Overview
A 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 VIN+ is less
than the analog voltage at VIN-, the output of the
comparator is a digital low level. When the analog
voltage at VIN+ is greater than the analog voltage at
VIN-, the output of the comparator is a digital high level.
FIGURE 8-1:
SINGLE COMPARATOR
VIN+
+
VIN-
–
Output
VIN-
VIN+
Output
Note:
The black areas of the output of the
comparator represents the uncertainty
due to input offsets and response time.
This device contains two comparators as shown in
Figure 8-2 and Figure 8-3. The comparators are not
independently configurable.
© 2007 Microchip Technology Inc.
DS41202F-page 55