PIC32MX1XX Datasheet, PDF (215/320 Pages) Microchip Technology – 32-bit Microcontrollers (up to 128 KB Flash and 32 KB SRAM) with Audio and Graphics Interfaces, USB, and Advanced Analog

PIC32MX1XX/2XX
23.0 COMPARATOR VOLTAGE
REFERENCE (CVREF)
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 (CVREF)” (DS61109)
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.
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 23-1. 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 CVREF 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 23-1:
COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM
VREF+
AVDD
CVRSS = 1
CVRSS = 0
CVRSRC
8R
CVREN
R
R
R
R
16 Steps
R
R
R
CVR<3:0>
CVREF
CVREFOUT
CVRCON<CVROE>
CVRR
VREF-
AVSS
8R
CVRSS = 1
CVRSS = 0
© 2011-2012 Microchip Technology Inc.
Preliminary
DS61168D-page 215