PIC18F67J11T-I Datasheet, PDF (327/466 Pages) Microchip Technology – 64/80-Pin, High-Performance, 1-Mbit Flash Microcontrollers

PIC18F87J11 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.
A block diagram of the module is shown in Figure 24-1.
The resistor ladder is segmented to provide two ranges
of CVREF 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 VDD/VSS or an external voltage reference.
FIGURE 24-1:
COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM
VREF+
CVRSS = 1
VDD
CVRSS = 0
8R
CVREN
R
R
R
R
16 Steps
CVRR
VREF-
R
R
R
CVRSS = 1
CVRSS = 0
CVR<3:0>
CVREF
8R
 2007-2012 Microchip Technology Inc.
DS39778E-page 327