Datasheet
2009-2013 Microchip Technology Inc. DS60001156H-page 335
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 CVREF output is avail-
able for the comparators and typically available for pin
output.
Key features of the CV
REF module include:
• 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 MODULE 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
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
CVROE (CVRCON<6>)
CV
REF
VREFSEL
(1)
IVREF
1.2V
0.6V
BGSEL<1:0>
(1)
CVRSRC
Note 1:
This bit is not available on PIC32MX575/675/695/775/795 devices. On these devices CV
REF
is generated by the
Register
network and IVREF is connected to 0.6V.