PIC18F67J11-IPT Datasheet, PDF (311/448 Pages) Microchip Technology – 64/80-Pin High-Performance, 1-Mbit Flash Microcontrollers with nanoWatt Technology

PIC18F87J11 FAMILY
23.0 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 23-1.
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 23-1:
COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM
VREF+
CVRSS = 1
VDD
CVRSS = 0
8R
CVREN
R
R
R
R
16 Steps
R
R
R
CVR3:CVR0
CVREF
CVRR
VREF-
8R
CVRSS = 1
CVRSS = 0
© 2009 Microchip Technology Inc.
DS39778D-page 311