PIC24FJ256GA106T-I Datasheet, PDF (229/292 Pages) Microchip Technology – 64/80/100-Pin, 16-Bit General Purpose Flash Microcontrollers with Peripheral Pin Select

PIC24FJ256GA110 FAMILY
22.0 COMPARATOR VOLTAGE
REFERENCE
Note:
This data sheet summarizes the features
of this group of PIC24F devices. It is not
intended to be a comprehensive reference
source. For more information, refer to the
“PIC24F Family Reference Manual”,
“Section 20. Comparator Voltage
Reference Module” (DS39709).
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
VREF+ ^{CVRSS = 1}
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
© 2008 Microchip Technology Inc.
Preliminary
DS39905B-page 227