Schwarzbeck CDN AF8 Coupling Decoupling Network

The Schwarzbeck CDN AF8 is part of the coupling decoupling network series for conducted common mode immunity testing according to IEC 61000-4-6. The CDN AF8 is compliant to IEC 61000-4-6 Figure D.6 and is suitable for immunity testing on unscreened unbalanced lines.

The CDN AF8 is intended to inject common mode disturbance signals to EuTs with unscreened unsymmetrical lines in the frequency range from 150 kHz to 230 MHz. The circuitry is shown in Fig. 5.

All CDNs comply to the requirements of IEC 61000-4-6. Each CDN comes with individually measured data and a calibration certificate for the common mode impedance (fig. 1) and the voltage division factor (fig.3). Further typical data can be found in fig. 2 and fig. 4

A variety of calibration adapters and other accessories are available as option.

Remarks for the use of the supplied calibration adapters:

For the calibration it is mandatory to short all lines to create the common mode case. For this purpose the supplied calibration adapter (CA 8/4) is used. Due to the number of contacts, a relatively high insertion force is neccessary. Especially for unplugging a suitable lever with smooth surfaces is recommended. It is advisable to lift the adapter left and right in an alternating way several times to prevent unintentional bending.

The capacitors at the AE-side are not equipped with discharging resistors.

The connection to ground can be accomplished using the ground plane of the CDN. Additionally there is a M4 thread located at the AE side to ground as well as a 4 mm socket to connect the device to ground.

To improve the operational safety the connections are carried out as security sockets. We recommend to use special 4 mm security plugs if you plan to design your own adapters. Those connectors can be purchased optionally.

Fig. 1: typ. EuT Common Mode Impedance	Fig. 2: typ. phase EuT-port, (common mode)
Fig. 3: typ. voltage division factor RF-port to EuT-port	Fig. 4: typ. isolation between AE and RF-Port