Datasheet

PIC16F630/676
DS40039E-page 38 © 2007 Microchip Technology Inc.
6.1 Comparator Operation
A single comparator is shown in Figure 6-1, along with
the relationship between the analog input levels and
the digital output. When the analog input at V
IN+ is less
than the analog input V
IN-, the output of the comparator
is a digital low level. When the analog input at V
IN+ is
greater than the analog input V
IN-, the output of the
comparator is a digital high level. The shaded areas of
the output of the comparator in Figure 6-1 represent
the uncertainty due to input offsets and response time.
The polarity of the comparator output can be inverted
by setting the CINV bit (CMCON<4>). Clearing CINV
results in a non-inverted output. A complete table
showing the output state versus input conditions and
the polarity bit is shown in Table 6-1.
TABLE 6-1: OUTPUT STATE VS. INPUT
CONDITIONS
FIGURE 6-1: SINGLE COMPARATOR
Note: To use CIN+ and CIN- pins as analog
inputs, the appropriate bits must be
programmed in the CMCON (19h) register.
Input Conditions CINV COUT
V
IN- > VIN+ 00
V
IN- < VIN+ 01
VIN- > VIN+ 11
VIN- < VIN+ 10
Output
V
IN-
VIN+
Output
+
–
V
IN+
V
IN-
Note: CINV bit (CMCON<4>) is clear.