Com-Power CDN-AF4, Руководство пользователя

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Model CDN -AF4
The IEC-1000-4-6 recommends putting coupling decoupling
networks on signal cables between the EUT and Auxillary
equipment.
Generally the stop frequency range for IEC-1000-4-6
requirement is 80 MHz. Some product specific standards may
require extending the stop frequency to 230 MHz when the
dimensions of device under test may be be less than
λ
/4. The
Com-Power CDNs can be used to meet this extended frequency
requirement.
2.2 Important CDN parameters
The most important characteristic when selecting CDN is to
insure that it meets the Common mode terminal impedance
specified in the IEC-1000-4-6. It would be also benificial to select
CDN with low attenuation and coupling factors. Please see
section 1 for typical measured values for these parameters for
Com-Power CDN-AF4
Common mode impedance parameters at the EUT port of the
CDN are given in table 2-1. This ensures that any circuit level
abnormal operation was caused by the injected RF signal on
the EUT and not the auxillary equipment (AE). The requirement
must be met with CDN auxillary input terminals open or short
circuited to ground.
2.2.2 Voltage attenuation
Attenuation is the amount of power that is lost between the
signal input terminal of the CDN and the EUT port. The IEC-
1000-4-6 specification does not specify the attenuation factor,
however it benificial to keep it low as possible. The attenuation
factor for the Com-Power CDN is approximately 10 dB for the
frequency range of 150 kHz - 80 MHz. The attenuation is useful
factor for predicting the amount of input power required to
generate required immunity voltage.
2.2.3 Coupling factor
The CDN coupling factor is defined as the open circuit voltage
obtained at the EUT (common mode) port devided by the open
circuit voltage obtained at the input connector. The coupling
factor value is not defined by IEC-1000-6 specification, but
2-2