Reliant EMC

CDNs - coupling-decoupling network

Laplace Instruments CDN - Coupling decoupling Network


Key Points

Laplace supply a wide range of CDNs that are fully compliant to IEC61000-4-6.

In addition to a range of 'conventional' CDNs, Laplace are unique in offering two other types. Both types are 'versatile' in that they are configurable, offering great flexibility in terms of the type of cable each model can be used with. This reduces the number of CDNs necessary to hold in stock. The final type is, in addition to being versatile, fitted with an output which monitors the RF level applied to the cable.


The three types are:
 Conventional CDNs. Compliant to IEC61000-4-6. 
Wide range of models to suit a wide variety of cable types
Compliant to IEC61000-4-6. Just 5 models. Each model is versatile and can be configured to suit a wide range of cable types. Over 25 different cable types can be accommodated by these 5 models.
Identical to the versatile type described above, but with the additional benefit of the inclusion of a feedback circuit and detector such that the applied stress level can be monitored and used (if required) as part of the level control system.
The Standard types are grouped into three classes:
The Versatile and Enhanced types are multi-functional. Each type includes just 5 basic models:
1. Mains power
2. Screened cables up to 25 cores
3. Unscreened cables up to 24 cores
4. Telecom cables to 8 cores
5. Telecom cables to 6 cores


In addition, the S46M5/9 is a multifunction CDN capable of 100A rating for M3 and M2 configuration, or 50A in M5 and M4 (three phase) configurations. This CDN also has an additional 4 cores rated at 6A for ground wire, control or sensing requirements.

Each model can be configured to cover a wide variety of cables, and still maintain full compliance with IEC61000-4-6.


The Enhanced models can be used in conjunction with a suitable signal generator such that closed loop level control can be achieved. This offers the advantages of greater efficiency, reduced RF power requirement and better accuracy for the applied RF level.


Note that the RFIC-4-6 synthesizer system from Laplace offers the capability to work with the enhanced CDNs (as well as standard and versatile types). Other synthesizers will not work in the 'enhanced' mode.

CDNs is an optional extra for the following products:

CIT-10 conducted immunity test system


CDNs appears in the following kits:

RFIC kit


Associated Downloads

Data Sheet - Versatile and Enhanced CDNs


Enhanced CDNs - Paper presented at the York EMC Symposium 1999


Conducted Immunity Products for IEC61000-4-6 Testing