POWER AND LINEAR IC SOLUTIONS

Circuit Protection For Every Port

Internet Access Devices (IADs) are evolving to provide more functionality. A modern ADSL2+ terminal adaptor, for example, often provides telephone voice, video and data communications for computers or networks. The combination of these three facilities is commonly known as triple play.



In triple play terminal adapter or premises equipment, all three ports need circuit protection. Bourns provides a full range of components to implement protection to standards such as UL60950 and TIA-968-A (Formerly FCC Pt. 68).

The xDSL port needs protection against hazards from the outside world, ranging from accidental shorting to lightning strikes and power surges. A device such as Bourns® TISP4xxx fixed-voltage single bidirectional thyristor surge protector is suitable for this purpose.

In theory the voice ports might appear not to need a high level of protection, since they should never leave the premises. However, field experience has repeatedly shown that extension leads often do leave the premises, rendering the system vulnerable to damage during lightning storms and AC disturbances. Telcordia Intrabuilding or ITU-T K.20 (basic) levels can be achieved by using the Bourns® TISP61089B dual programmable thyristor surge protector. This arrangement provides lightning/surge protection up to 500A to Telcordia GR-1089-CORE, ANSI C62.41 and ITU-T K.20/21.

It is also important not to neglect the USB and LAN data ports and the power supply unit that is used to generate the various DC levels needed by such an IAD. Both types of circuit can be protected with Bourns® Multifuse® polymer Positive Temperature Coefficient (PTC) resettable fuses. These are available in a variety of form-factors, depending on the application: a typical choice in an IAD would be the MF-MSMF110 device.



Bourns® Circuit Protection Products

• Gas discharge tubes
• MSP® hybrid protectors
• Signal and dataline protectors
• Multifuse® polymer PTC resettable fuses
• Line protection modules
• Telefuse™ telecom fuses
• ChipGuard® ESD protectors
• Transient Voltage Suppression (TVS) diodes
• TISP® thyristor surge protectors

Applications

• Customer premises equipment
• Triple play terminal adapters
• Central office equipment
• Access equipment

For further information, including Circuit Protection device Samples, Datasheets and Product Brochure, please click here