AD8141/AD8142
TERMINOLOGY
Differential Voltage
Differential voltage refers to the difference between two node
voltages that are balanced with respect to each other. For example,
in Figure 36, the output differential voltage (or output differential
mode voltage) is defined as
VOUT, dm = (VOP − VON)
Common-mode voltage refers to the average of two node voltages
with respect to a common reference (usually the local ground).
The output common-mode voltage is defined as
VOUT ,cm
=
(VOP
+ VON
2
)
Output Balance
Output balance is a measure of how well the differential output
signals are matched in amplitude and how close they are to exactly
180° apart in phase. Balance can be easily determined by placing a
well-matched resistor divider between the differential output
voltage nodes and comparing the magnitude of the signal at the
divider’s midpoint with the magnitude of the differential signal.
By this definition, output balance error is the magnitude of the
change in output common-mode voltage divided by the magnitude
of the change in output differential-mode voltage in response to
a differential input signal.
Output Balance
Error =
ΔVOUT ,cm
ΔVOUT ,dm
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