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1
0
CDON
CDREF0
5
V
CC
5
1
0
1
0
C
D
R
S
=
1
1
01
10
00, 11
CDRSx
2
V
REF
V
REF1
V
REF0
1.2 V from the
shared reference
CDREFLx
1
0
CDMRVS
CDMRVL
2
CDREF1
+ Terminal
− Terminal
Comparator Inputs
Comparator Output
Unfiltered at CDOUT
Comparator Output
Filtered at CDOUT
Comparator_D Operation
Figure 17-3. RC-Filter Response at the Output of the Comparator
17.2.6 Reference Voltage Generator
The Comparator_D reference block diagram is shown in
Figure 17-4. Reference Generator Block Diagram
The voltage reference generator is used to generate VREF, which can be applied to either comparator
input terminal. The CDREF1x (VREF1) and CDREF0x (VREF0) bits control the output of the voltage
generator. The CDRSEL bit selects the comparator terminal to which VREF is applied. If external signals
are applied to both comparator input terminals, the internal reference generator should be turned off to
reduce current consumption. The voltage reference generator can generate a fraction of the device's V
CC
or of the voltage reference of the integrated precision voltage reference source. Vref1 is used while
CDOUT is 1 and Vref0 is used while CDOUT is 0. This allows the generation of a hysteresis without using
external components.
466
Comparator_D
SLAU272C – May 2011 – Revised November 2013
Copyright © 2011–2013, Texas Instruments Incorporated