BOURNS TISP4P035L1NR-S

This series of devices is designed to protect xDSL line driver interfaces against overvoltages up to rated limits. Overvoltages are typically caused by AC power systems or lightning disturbances that are induced or conducted onto telephone lines. These symmetrical protectors are two-terminal thyristor clamping devices. They can be used for conductor-to-conductor protection, or a pair of devices can be deployed for line-to-ground protection.

When placed between the xDSL line driver IC and the transformer, the protector clamps and switches to a low-impedance state, safely diverting energy transmitted through the xDSL coupling transformer. The low-capacitance design makes the device suitable for designs ranging from ADSL to 30 MHz VDSL2.

Telecom ports require protection against both common-mode (longitudinal) and differential-mode (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 rejected by the galvanic isolation of the coupling transformer, which typically carries a rating of ≥1 kV or higher. Differential-mode surges can pass through the transformer and may stress the interface driver IC. Since xDSL interface circuits are designed to operate in the 3 kHz to 30 MHz range, nearby high-frequency events — such as cable flashover or primary protector activation — can create damaging conditions at the interface, necessitating this type of protection.