Differential Mode And Common Mode; Differential Mode Range And Common Mode Range - LeCroy AP034 Instruction Manual

5HIHUHQFH ,QIRUPDWLRQ

DIFFERENTIAL MODE AND COMMON MODE

DIFFERENTIAL MODE RANGE AND COMMON MODE RANGE

AP034-OM-E Rev D
Differential probes amplify the voltage difference that appears
between the + and – inputs. This voltage is referred to as the
Differential Mode or Normal Mode voltage. The voltage
component that is referenced to earth ground, and is identical on
both inputs, is rejected by the amplifier. This voltage is referred to
as the Common Mode voltage, because it is common to both
inputs. The common mode voltage can be expressed as:
V
CM
The Differential Mode Range is the maximum signal that can be
applied between the + and – inputs without overloading the probe
amplifier, resulting in "clipping" or distortion of the waveform
measured by the oscilloscope.
The Common Mode Range is the maximum voltage with respect
to earth ground that can be applied to either input. Exceeding the
common mode range can result in unpredictable results.
Because the Common Mode signal is normally rejected, and is
not displayed on the oscilloscope, you need to be careful to avoid
accidentally exceeding the common mode range.
ISSUED: January 2000
5HIHUHQFH ,QIRUPDWLRQ
V + V
+Input -Input
=
2
²