DESCRIPTION
Overvoltages are normally caused by a.c. power-system or lightning-flash disturbances which are (Ring) induced or conducted onto the telephone line. They can be used to protect between conductors, or a pair of devices can be deployed to protect from line to ground. When placed between the xDSL line driver IC and the transformer, this protector will clamp and switch into a low-impedance state, safely diverting the energy transferred by the xDSL coupling transformer. The low capacitance design makes this device suitable for designs from ADSL all the way up to 30 MHz VDSL2. Telecom ports need protection against Common Mode (Longitudinal) and Differential (Metallic) surges, to comply with international standards such as ITU-T K.20, K.21 or K.45, Telcordia GR-1089-CORE and YD/T. Common Mode surges are resisted by the galvanic isolation of the coupling transformer which is commonly rated to 2 kV or greater. Differential surges can be transmitted by the transformer, and can stress the Line Driver Interface IC.
Bourns
