ada4939-1 Analog Devices, Inc., ada4939-1 Datasheet - Page 16

• Manufacturer Part Number: ada4939-1
• Description: Ultralow Distortion Differential Adc Driver
• Manufacturer: Analog Devices, Inc.

ADA4939-1/ADA4939-2
OPERATIONAL DESCRIPTION
DEFINITION OF TERMS
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
where V
−OUT terminals with respect to a common reference.
V
V
+D
OUT, dm
–D
OCM
+FB
–FB
IN
IN
+OUT
= (V
and V
R
R
G
G
R
R
+OUT
F
F
−OUT
Figure 42. Circuit Definitions
+IN
–IN
− V
refer to the voltages at the +OUT and
−OUT
ADA4939
)
–OUT
+OUT
R
L, dm
V
OUT, dm
Rev. 0 | Page 16 of 24
Common-Mode Voltage
Common-mode voltage refers to the average of two node
voltages. The output common-mode voltage is defined as
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 divider midpoint
with the magnitude of the differential signal (see Figure 39). By
this definition, output balance is the magnitude of the output
common-mode voltage divided by the magnitude of the output
differential mode voltage.
V
Output
OUT, cm
= (V
Balance
+OUT
+ V
Error
−OUT
=
)/2
V
V
OUT
OUT
,
,
dm
cm