PIC32MX440F256H-80I Datasheet, PDF (551/646 Pages) Microchip Technology – 64/100-Pin General Purpose and USB 32-Bit Flash Microcontrollers

PIC32MX3XX/4XX
25.0 COMPARATOR REFERENCE
Note:
This data sheet summarizes the features of
the PIC32MX3XX/4XX family of devices. It
is not intended to be a comprehensive refer-
ence source. Refer to the “PIC32MX Family
Reference Manual” (DS61132) for a
detailed description of this peripheral.
The Comparator Voltage Reference (CVREF) 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 shown in Figure 25-1.
The resistor ladder is segmented to provide two ranges
of voltage reference values and has a power-down func-
tion to conserve power when the reference is not being
used. The module’s supply reference can be provided
from either device VDD/VSS or an external voltage refer-
ence. The CVREF output is available for the comparators
and typically available for pin output. Please see the
specific device data sheet for information.
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 25-1:
COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM
VREF+
CVRSS = 1
AVDD
CVRSS = 0
8R
CVREN
R
R
R
R
16 Steps
CVRR
VREF-
AVSS
R
R
R
CVRSS = 1
CVRSS = 0
CVR3:CVR0
CVREF_IN
CVREF
CVRCON<CVROE-
8R
© 2008 Microchip Technology Inc.
Preliminary
DS61143E-page 549