Datasheet
DATA CONVERTERS
V
IN
-
+
-
+
DV
DD
V
OCM
AV
SS
AV
DD
A
IN2
A
IN1
V
DD
V
ref
5 V
V
CC
0.1 µF
-5 V
V
CC
-
V
IN
-
+
-
+
DV
DD
V
OCM
AV
SS
AV
DD
A
IN2
A
IN1
V
DD
V
ref
5 V
V
CC
0.1 µF
V
IN
-
+
-
+
DV
DD
V
OCM
AV
SS
AV
DD
A
IN2
A
IN1
V
DD
V
ref
5 V
V
CC
0.1 µF
V
CC
R
PU
V
CC
R
PU
THS1206
R
(g)
R
(g)
V
P
R
f
R
f
V
OUT
V
OUT
THS4150
THS4151
SLOS321G – MAY 2000 – REVISED MARCH 2009 ...........................................................................................................................................................
www.ti.com
Data converters are one of the most popular applications for the fully differential amplifiers. The following
schematic shows a typical configuration of a fully differential amplifier attached to a differential ADC.
Figure 31. Fully Differential Amplifier Attached to a Differential ADC
Fully differential amplifiers can operate with a single supply. V
OCM
defaults to the midrail voltage, V
CC
/2. The
differential output may be fed into a data converter. This method eliminates the use of a transformer in the circuit.
If the ADC has a reference voltage output (V
ref
), then it is recommended to connect it directly to the V
OCM
of the
amplifier using a bypass capacitor for stability. For proper operation, the input common-mode voltage to the input
terminal of the amplifier should not exceed the common-mode input voltage range.
Figure 32. Fully Differential Amplifier Using a Single-Supply
Some single-supply applications may require the input voltage to exceed the common-mode input voltage range.
In such cases, the following circuit configuration is suggested to bring the common-mode input voltage within the
specifications of the amplifier.
Figure 33. Circuit With Improved Common-Mode Input Voltage
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