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Overcurrent protection suits telecomms linecards

A Raychem Circuit Protection product story

Edited by the Electronicstalk editorial team Jul 19, 2005

The PolySwitch TSM600-400 is a low-resistance resettable overcurrent protection device for communications infrastructure applications.

Available now from Raychem Circuit Protection, the PolySwitch TSM600-400 is a low-resistance resettable overcurrent protection device for communications infrastructure applications.

This RoHS-compliant device helps equipment comply with recent worldwide telecommunications standards, such as Telcordia GR-1089 Issue 3, UL60950 3rd edition and TIA-968-A (formerly FCC Part 68), and can also be used in systems designed to ITU-T K.21 and K.21 recommendations.

The PolySwitch TSM600-400 device, with its surface-mount configuration, small footprint and low resistance is designed for use in high-density multiport linecards and other space-constrained communications network equipment.

The TSM600-400 device incorporates two matched, low-resistance PPTC (polymeric positive temperature coefficient) components in a single package, yielding highly balanced resistance characteristics.

This newly developed PolySwitch device is primarily intended for use in "earthed" communications systems such as POTS and xDSL linecards.

"The TSM600-400 device's resettable functionality helps improve network reliability, reduce maintenance and repair costs, and enhance user satisfaction", said Boris Golubovic, Global Marketing Manager for Raychem Circuit Protection.

"Combining a TSM600-400 device with SiBar thyristor surge protector devices or Raychem Circuit Protection gas discharge tubes helps equipment designers comply with the lightning and AC power fault protection requirements defined in Telcordia GR-1089 Issue 3 that are scheduled to go into effect in 2006".

Each of the two resettable overcurrent protection components in the TSM600-400 device has a typical resistance of 1.2ohm, and the two components are typically matched to better than 0.3ohm.

In addition to interrupting AC power faults, the device is designed to help equipment comply with Telcordia GR-1089 Issue 3 lightning tests, and has a rated hold current of 400mA at room temperature.

This device is designed for operating temperatures between -40 and +85C, and withstands soldering temperatures of up to 260C for 60s maximum.

The devices are tape and reel packaged for compatibility with high-volume assembly processes.