PIC24FJ128GA Datasheet, PDF (179/232 Pages) Microchip Technology – General Purpose, 16-Bit Flash Microcontrollers

PIC24FJ128GA FAMILY
22.0 COMPARATOR VOLTAGE
REFERENCE
Note:
This data sheet summarizes the features
of this group of PIC24FJ devices. It is not
intended to be a comprehensive reference
source.
22.1 Configuring the Comparator
Voltage Reference
The voltage reference module is controlled through the
CVRCON register (Register 22-1). The comparator
voltage reference provides two ranges of output
voltage, each with 16 distinct levels. The range to be
used is selected by the CVRR bit (CVRCON<5>). The
primary difference between the ranges is the size of the
steps selected by the CVREF Selection bits
(CVR3:CVR0), with one range offering finer resolution.
The comparator reference supply voltage can come
from either VDD and VSS, or the external VREF+ and
VREF-. The voltage source is selected by the CVRSS
bit (CVRCON<4>).
The settling time of the comparator voltage reference
must be considered when changing the CVREF
output.
FIGURE 22-1:
COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM
CVRSS = 1
VREF+
AVDD
CVRSS = 0
8R
CVREN
R
R
R
R
16 Steps
CVR3:CVR0
CVREF
R
R
R
CVRR
VREF-
8R
CVRSS = 1
CVRSS = 0
AVSS
© 2006 Microchip Technology Inc.
Preliminary
DS39747C-page 177