Datasheet

© 2011-2014 Microchip Technology Inc. DS60001168F-page 215
PIC32MX1XX/2XX
23.0 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.
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 reference can be pro-
vided from either device V
DD/VSS or an external
voltage reference. The CVREF output is available 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
A block diagram of the module is shown in Figure 23-1.
FIGURE 23-1: COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM
Note 1: This data sheet summarizes the
features of the PIC32MX1XX/2XX
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