Teledyne LeCroy ADP300_305 - Manual (Page 32)

ADP30x Probe
The first order term that determines the CMRR is the relative gain matching
between the + and – input paths. To obtain high CMRR values, the input
attenuators in a differential amplifier are precisely matched to each other. This
matching includes the DC attenuation as well as the capacitance that determines
the AC attenuation. As the frequency of the common mode component
increases, the effects of stray parasitic capacitance and inductance in
determining the AC component becomes more pronounced. The CMRR becomes
smaller as the frequency increases. Hence, the CMRR is usually specified in a
graph of CMRR versus common mode frequency.
The common mode frequency in these graphs is assumed to be sinusoidal. In
real life applications, the common mode signal is seldom a pure sine wave.
Signals with pulse wave shapes contain frequency components much higher
than the repetition rate may suggest. As such, it is very difficult to predict actual
performance in the application for CMRR versus frequency graphs. The practical
application of these graphs is to compare the relative common mode rejection
performance between different amplifiers.
Certifications
This section certifies the ADP30x probe’s Electromagnetic Compatibility (EMC),
Safety and Environmental compliances.
EMC Compliance
EC D
ECLARATION OF
C
ONFORMITY
- EMC
The probe meets intent of EC Directive 2004/108/EC for Electromagnetic
Compatibility. Compliance was demonstrated to the following specifications as
listed in the Official Journal of the European Communities:
EN 61326-1:2006, EN 61326-2-1:2006 EMC requirements for electrical
equipment for measurement, control, and laboratory use.
Electromagnetic Emissions:
CISPR 11:2003, Radiated and Conducted Emissions Group 1, Class A 1 2
Electromagnetic Immunity:
EN 61000-4-2:2001 Electrostatic Discharge, 4 kV contact, 8 kV air, 4 kV
vertical/horizontal coupling planes 3
28 923079-00 Rev A