Microchip Technology MA330019 Ficha De Dados

© 2007-2012 Microchip Technology Inc.

DS70291G-page  307

24.3.1

CONFIGURING THE COMPARATOR 
VOLTAGE REFERENCE

The voltage reference module is controlled through the 
CVRCON register (

). 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 CV

REF

 Selection bits 

(CVR3:CVR0), with one range offering finer resolution. 

The comparator reference supply voltage can come 
from either V

DD

 and V

SS

, or the external V

REF

+ and 

V

REF

-. 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 CV

REF

output.

16-

to-1 MUX

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

REF

CVR3

CVR2

CVR1

CVR0

CVRCON<3:0>

AV

SS

CV

RSRC

CVROE (CVRCON<6>)

CV

REFIN