Datasheet

ADA4932-1/ADA4932-2 Data Sheet
Rev. B | Page 18 of 28
TERMINOLOGY
+IN
–IN
+OUT
–OUT
+D
IN
–FB
+FB
–D
IN
V
OCM
R
G
R
F
R
G
V
OUT, dm
R
L, dm
R
F
ADA4932-x
07752-046
Figure 55. Signal and Circuit Definitions
Differential Voltage
Differential voltage refers to the difference between two
node voltages. For example, the output differential voltage (or
equivalently, output differential mode voltage) is defined as
V
OUT, dm
= (V
+OUT
− V
−OUT
)
where V
+OUT
and V
−OUT
refer to the voltages at the +OUT and
−OUT terminals with respect to a common ground reference.
Similarly, the differential input voltage is defined as
V
IN, dm
= (+D
IN
− (−D
IN
))
Common-Mode Voltage
Common-mode voltage refers to the average of two node voltages
with respect to the local ground reference. The output common-
mode voltage is defined as
V
OUT, cm
= (V
+OUT
+ V
−OUT
)/2
Balance
Output balance is a measure of how close the output differential
signals are to being equal in amplitude and opposite in phase.
Output balance is most easily determined by placing a well-
matched resistor divider between the differential voltage nodes
and comparing the magnitude of the signal at the divider midpoint
with the magnitude of the differential signal (see Figure 53). By
this definition, output balance is the magnitude of the output
common-mode voltage divided by the magnitude of the output
differential mode voltage.
dmOUT
cm
OUT
V
V
Error
Balance
Output
,
,
∆
∆
=