Short line protection

AN2053

12/15

Doc ID 10917 Rev 2

5

Short line protection

The short line concept is used in case of new telecom networks. This kind of line is linked to

the new applications like WLL, fiber on the corner, NT1+, phone over cable TV network,

telecom by 50/60 Hz supply network etc. Their need for battery voltage as well as the

ringing voltage is lower than those for long line applications. This allows the use of a new

generation of high voltage SLIC circuit which can be either single or double voltage

supplied.

Figure 17.

Short line application using high voltage SLIC

Figure 18.

Short line application using SLIC with positive and negative voltages

SLIC

-V bat

Line

Tip

Ring

PTC or Fuse

PTC or Fuse

(*)

(*)

(*) Not mandatory

LCP1521S

LCP02-150B1

SLIC

-V bat

+V b

Line

Tip

Ring

PTC or Fuse

PTC or Fuse

(*)

(*)

(*) Not mandatory

+V b