Datasheet

Data Sheet ADA4937-1/ADA4937-2
Rev. D | Page 17 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
ADA4937
06591-049
Figure 52. 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 reference.
Common-Mode Voltage
Common-mode voltage refers to the average of two node
voltages. The output common-mode voltage is defined as
V
OUT, cm
= (V
+OUT
+ V
−OUT
)/2
Output Balance
Output balance is a measure of how close the 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 midpoint of the
divider with the magnitude of the differential signal (see Figure
50). 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
cmOUT
V
V
ErrorBalanceOutput
,
,
=