27.21
Analog Comparator
Table 27-58. Analog Comparator Characteristics
ab
Unit
Max
Nom
Min
Parameter Name
Parameter
V
V
DDA
-
GNDA
Input voltage range
V
INP
,V
INN
c
V
V
DDA
-
GNDA
Input common mode voltage range
V
CM
mV
±50
d
±10
-
Input offset voltage
V
OS
µA
2.0
-
-
Input leakage current over full voltage range
I
INP
,I
INN
dB
-
50
-
Common mode rejection ratio
C
MRR
µs
1.0
e
-
-
Response time
T
RT
µs
10
-
-
Comparator mode change to Output Valid
T
MC
a. Best design practices suggest that static or quiet digital I/O signals be configured adjacent to sensitive analog inputs to
reduce capacitive coupling and cross talk.
b. To achieve best analog results, the source resistance driving the analog inputs, V
INP
and V
INN
, should be kept low.
c. The external voltage inputs to the Analog Comparator are designed to be highly sensitive and can be affected by external
noise on the board. For this reason,
V
INP
and
V
INN
must be set to different voltage levels during idle states to ensure the
analog comparator triggers are not enabled. If an internal voltage reference is used, it should be set to a mid-supply
level. When operating in Sleep/Deep-Sleep modes, the Analog Comparator module should be disabled or the external
voltage inputs set to different levels (greater than the input offset voltage) to achieve minimum current draw.
d. Measured at VREF=100 mV.
e. Measured at external VREF=100 mV, input signal switching from 75 mV to 125 mV.
Table 27-59. Analog Comparator Voltage Reference Characteristics
Unit
Max
Nom
Min
Parameter Name
Parameter
V
-
V
DDA
/29.4
-
Resolution in high range
R
HR
V
-
V
DDA
/22.12
-
Resolution in low range
R
LR
V
±R
HR
/2
-
-
Absolute accuracy high range
A
HR
V
±R
LR
/2
-
-
Absolute accuracy low range
A
LR
Table 27-60. Analog Comparator Voltage Reference Characteristics, V
DDA
= 3.3V, EN= 1, and
RNG = 0
Unit
V
IREF
Max
Ideal V
IREF
V
IREF
Min
VREF
Value
V
0.841
0.786
0.731
0x0
V
0.953
0.898
0.843
0x1
V
1.065
1.010
0.955
0x2
V
1.178
1.122
1.067
0x3
V
1.290
1.235
1.180
0x4
V
1.402
1.347
1.292
0x5
V
1.514
1.459
1.404
0x6
V
1.627
1.571
1.516
0x7
V
1.739
1.684
1.629
0x8
V
1.851
1.796
1.741
0x9
V
1.963
1.908
1.853
0xA
V
2.076
2.020
1.965
0xB
V
2.188
2.133
2.078
0xC
1877
June 18, 2014
Texas Instruments-Production Data
Tiva
™
TM4C1294NCPDT Microcontroller