AD8141/AD8142

Data Sheet

Rev. B | Page 14 of 24

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

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

2

)

(

,

ON

OP

cm

OUT

V

V

V

+

=

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.

dm

OUT

cm

OUT

V

V

Error

Balance

Output

,

,

∆

∆

=