Datasheet

 2010 Microchip Technology Inc. Preliminary DS39974A-page 387
PIC18F47J13 FAMILY
24.0 COMPARATOR VOLTAGE
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.
Figure 24-1 provides a block diagram of the module.
The resistor ladder is segmented to provide two ranges
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
DD/VSS or an external voltage reference.
FIGURE 24-1: COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM
16-to-1 MUX
CVR<3:0>
8R
R
CVREN
CVRSS = 0
V
DD
VREF+
CVRSS = 1
8R
CVRSS = 0
V
REF-
CVRSS = 1
R
R
R
R
R
R
16 Steps
CVRR
CVREF