Coupling/decoupling network for telecom surge testing

January 21, 2013 // By Jean-Pierre Joosting
Teseq has designed a CDN (coupling/decoupling network) for surge testing on unshielded symmetrical high speed telecommunication lines including Ethernet. The CDN HSS-2 enables convenient surge testing with 1.2/50 µs pulses on active telecom lines.

Ideal for use in laboratories, Teseq’s CDN HSS-2 is compliant with IEC 61000-4-5 and is compatible with all industry standard surge generators. It can be used for surge testing on lines with up to 8-wire unshielded twisted pair (UTP), with integrated service digital networks (ISDN) as well as with 10/100 BaseT and 1000 BaseT.

The CDN HSS-2 is compact, relatively lightweight and easy-to-use. It features selectable common mode coupling to 1, 2 or 4 pairs depending on the jumper settings on the CDN, and is coupled with 40 Ω in series with a coupling capacitor.

The new network features a maximum surge test voltage of 2 kV with a maximum peak surge test current of up to 50 A and a maximum residual voltage at the auxiliary equipment (AE) of only 65 V.

The device has a maximum operating speed of 1000 BaseT, maximum operating voltage of 100 VDC between pairs and maximum operating current of 1 A that is rated for power over Ethernet (PoE). Additional decoupling elements are not required to protect the AE. The unit’s high decoupling provides the AE independent pulse shape for the EUT.

The CDN HSS-2 weighs approximately 15 kg (33 lbs) and is 200 mm (7.8”) wide, 200 mm (7.8”) high and 470 mm (18.5”) deep.