Datasheet

 2012-2013 Microchip Technology Inc. DS60001185C-page 243
PIC32MX330/350/370/430/450/470
24.0 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 24-1. 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 VDD/VSS or an
external voltage reference. The CV
REF output is avail-
able for the comparators and typically available for pin
output.
The CVREF module 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 24-1: COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM
Note 1: This data sheet summarizes the features
of the PIC32MX330/350/370/430/450/
470 family of devices. It is not intended to
be a comprehensive reference source.
To complement the information in this
data sheet, refer to Section 20.
“Comparator Voltage Reference
(CV
REF)” (DS60001109) in the “PIC32
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
available 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
CVRSRC