
ADA4432-1/ADA4433-1
Data Sheet
Rev. A | Page 18 of 28
ENDED INPUT SIGNALS
used as a single-ended-to-differential amplifier or as a differential-
to-differential amplifier. In single-ended-to-differential output
applications, bias the IN input appropriately to optimize the
output range. To make the most efficient use of the output range
of th
e ADA4433-1, especially with low supply voltages, it is
important to allow the differential output voltage to swing in
both a positive and negative direction around the output common-
mode voltage (VOCM) level, the midsupply point. To do this, the
differential input voltage must swing both positive and negative.
Figure 46 shows a 1 V p-p single-ended signal on +IN with IN
grounded. This produces a differential input voltage that ranges
from 0 V to 1 V. The resulting differential output voltage is
strictly positive, where each output swings only above V+OUT or
below VOUT, the midsupply VOCM level. Directly at the output of the
ADA4433-1, the output voltage extends from 0.65 V to 2.65 V,
requiring a full 2 V of output to produce a 1 V p-p signal at the
receiver (represented by the voltage across 2R).
To make a more efficient use of the output range, the IN input is
biased at the midpoint of the expected input signal range, as shown
biased at 0.5 V, produces a differential input voltage that ranges
from 0.5 V to +0.5 V. The resulting differential output voltage
now contains both positive and negative components, where
each output swings both above and below the midsupply VOCM
voltage now extends only from 1.15 V to 2.15 V, requiring only
1 V of the output to produce a 1 V p-p signal at the receiver.
Figure 46. Single-Ended-to-Differential Configuration with Negative Input (IN) Connected to Ground
Figure 47. Single-Ended-to-Differential Configuration with Negative Input (IN) Connected to 0.5 V
INPUT SIGNAL
ADA4433-1
V+IN
VOCM =
1.65V
V+OUT
V–OUT
+
–
V–IN
VDIFF (IN) = V+IN – V–IN
VDIFF (OUT) = V+OUT – V–OUT
VOUT = VDIFF (OUT) ÷ 2
VOUT
R
2R
2.65V
0.65V
R
0V
1.0V
1V p-p
DIFFERENTIAL OUTPUT SIGNAL
DIFFERENTIAL OUTPUT SIGNAL ACROSS 2R
1V p-p
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028
INPUT SIGNAL
ADA4433-1
VOCM =
1.65V
+
–
VDIFF (IN) = V+IN – V–IN
VDIFF (OUT) = V+OUT – V–OUT
VOUT = VDIFF (OUT) ÷ 2
VOUT
R
2R
1.15V
2.15V
R
0V
0.5V
1.0V
1V p-p
DIFFERENTIAL OUTPUT SIGNAL
DIFFERENTIAL OUTPUT SIGNAL ACROSS 2R
1V p-p
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029
V+IN
V+OUT
V–OUT
V–IN