PIC32MX5XX_11 Datasheet, PDF (161/256 Pages) Microchip Technology – High-Performance, USB, CAN and Ethernet 32-bit Flash Microcontrollers

PIC32MX5XX/6XX/7XX
26.0 COMPARATOR VOLTAGE
REFERENCE (CVREF)
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 (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 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 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 26-1:
COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM
BGSEL<1:0>⁽¹⁾
1.2V
0.6V
IVREF
VREFSEL⁽¹⁾
VREF+
AVDD
CVRSS = 1
CVRSS = 0
CVRSRC
8R
CVREN
R
R
R
R
16 Steps
R
R
R
CVR<3:0>
CVREF
CVREFOUT
CVROE (CVRCON<6>)
CVRR
8R
VREF-
CVRSS = 1
AVSS
CVRSS = 0
Note 1: This bit is not available on PIC32MX575/675/695/775 devices. On these devices CVREF is generated by the Register
network and IVREF is connected to 0.6V.
© 2009-2011 Microchip Technology Inc.
DS61156G-page 161