Microchip Technology DV164136 Data Sheet
2007-2012 Microchip Technology Inc.
DS39778E-page 327
PIC18F87J11 FAMILY
24.0
COMPARATOR VOLTAGE
REFERENCE MODULE
REFERENCE MODULE
The comparator voltage reference is a 16-tap resistor
ladder network that provides a selectable reference
voltage. Although its primary purpose is to provide a
reference for the analog comparators, it may also be
used independently of them.
ladder network that provides a selectable reference
voltage. Although its primary purpose is to provide a
reference for the analog comparators, it may also be
used independently of them.
A block diagram of the module is shown in
The resistor ladder is segmented to provide two ranges
of CV
of CV
REF
values and has a power-down function to
conserve power when the reference is not being used.
The module’s supply reference can be provided from
either device V
The module’s supply reference can be provided from
either device V
DD
/V
SS
or an external voltage reference.
FIGURE 24-1:
COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM
1
6
-t
o
-1
MU
X
CVR<3:0>
8R
R
CVREN
CVRSS = 0
V
DD
V
REF
+
CVRSS = 1
8R
CVRSS = 0
V
REF
-
CVRSS = 1
R
R
R
R
R
R
16 Steps
CVRR
CV
REF