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AN1220

APPLICATION NOTE

®

LINECARD PROTECTION BY OVERVOLTAGE

AND OVERCURRENT WITH A CLP270M

A.S.D

ä

P.Merceron / A.Bremond

January 2000

This device includes a primary protection level and is suitable for main distribution frames and line cards.

This protection concept is explained and, in addition, the CLP270M performances are analysed when

facing different surges as described in the BELLCORE GR 1089 recommendations.

Figure 1 is a simplified block diagram of a subscriber line protection that is commonly used.

INTRODUCTION

CLP270M

CLP270M

SLIC

SLIC

THDTxx

or

LCP1511D

or

LCDP1511D

“PRIMARY PROTECTION”

“SECONDARY PROTECTION”

“SECONDARY PROTECTION”

Telecommunication

line

Telecommunication

line

MDF

EXCHANGE

EXCHANGE

LINE CARD

LINE CARD

MDF

Fig. 1: Subscriber line protection topology

This shows two different topologies :

n

A “primary protection” located on the Main Distribution Frame (MDF) eliminates coarsely the high energy

environmental disturbances (lightning transients and AC power mains disturbances)

n

A “secondary protection” located on the line card includes a primary protection level (first stage) and a

residual protection (second stage) which eliminates finely the remaining transients that have not been totally

suppressed by the first stage.

Obsolete

Product(s)

- Obsolete

Product(s)

Obsolete

Product(s)

- Obsolete

Product(s)