Datasheet

© 2010 Microchip Technology Inc. DS61156D-page 151
PIC32MX5XX/6XX/7XX
26.0 COMPARATOR VOLTAGE
REFERENCE (CVREF)
The CVREF module 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 also may be used independently
of them.
A block diagram of the module is illustrated in
Figure 26-1. The resistor ladder is segmented to
provide two ranges of voltage reference values and has
a power-down function to conserve power when the
reference is not being used. The module’s supply refer-
ence can be provided from either device V
DD/VSS or an
external voltage reference. The CV
REF output is avail-
able for the comparators and typically available for pin
output.
The comparator voltage reference has the following
features:
• High and low range selection
• Sixteen output levels available for each range
• Internally connected to comparators to conserve
device pins
• Output can be connected to a pin
FIGURE 26-1: COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM
Note 1: This data sheet summarizes the features
of the PIC32MX5XX/6XX/7XX family of
devices. It is not intended to be a compre-
hensive reference source. To complement
the information in this data sheet, refer to
Section 20. “Comparator Voltage
Reference (CVREF)” (DS61109) in the
“PIC32MX Family Reference Manual”,
which is available from the Microchip web
site (www.microchip.com/PIC32).
2: Some registers and associated bits
described in this section may not be avail-
able on all devices. Refer to
Section 4.0
“Memory Organization” in this data
sheet for device-specific register and bit
information.
16-to-1 MUX
CVR<3:0>
8R
R
CVREN
CVRSS = 0
AV
DD
VREF+
CVRSS = 1
8R
CVRSS = 0
V
REF-
CVRSS = 1
R
R
R
R
R
R
16 Steps
CVRR
CVREFOUT
AVSS
CVRCON<CVROE>
CV
REF