Datasheet
2009-2016 Microchip Technology Inc. DS60001156J-page 327
PIC32MX5XX/6XX/7XX
27.0 COMPARATOR VOLTAGE
REFERENCE (CV
REF
)
The CV
REF
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 27-1. 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
/V
SS
or an
external voltage reference. The CV
REF
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 27-1: COMPARATOR VOLTAGE REFERENCE MODULE BLOCK DIAGRAM
Note: 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 com-
plement 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).
16-to-1 MUX
CVR<3:0>
8R
R
CVREN
CVRSS = 0
AV
DD
V
REF
+
CVRSS = 1
8R
CVRSS = 0
V
REF
-
CVRSS = 1
R
R
R
R
R
R
16 Steps
CVRR
CV
REFOUT
AV
SS
CVROE (CVRCON<6>)
CV
REF
V
REFSEL
(1)
IV
REF
1.2V
0.6V
BGSEL<1:0>
(1)
CV
RSRC
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 IV
REF
is connected to 0.6V.