Datasheet

 2010 Microchip Technology Inc. DS41302D-page 77
PIC12F609/615/617/12HV609/615
9.11 Comparator Hysteresis
Each comparator has built-in hysteresis that is user
enabled by setting the CMHYS bit of the CMCON1
register. The hysteresis feature can help filter noise and
reduce multiple comparator output transitions when the
output is changing state.
Figure 9-7 shows the relationship between the analog
input levels and digital output of a comparator with and
without hysteresis. The output of the comparator
changes from a low state to a high state only when the
analog voltage at V
IN+ rises above the upper
hysteresis threshold (V
H+). The output of the
comparator changes from a high state to a low state
only when the analog voltage at V
IN+ falls below the
lower hysteresis threshold (V
H-).
FIGURE 9-7: COMPARATOR HYSTERESIS
–
+
VIN+
V
IN-
Output
Note: The black areas of the comparator output represents the uncertainty due to input offsets and response time.
VH-
V
H+
VIN-
V+
V
IN+
Output
(Without Hysteresis)
Output
(With Hysteresis)