AN2053 Datasheet, PDF (1/15 Pages) STMicroelectronics – SLIC protection for both classical and new networks

AN2053
Application note
SLIC protection for both classical and new networks
Introduction
Even with booming digital technologies, telecom analog lines remain the most used link in
the world. The market opening to new operators, reserved so far to national telecom
administration, makes an increase of new applications using this simple and cheap way to
supply speech information. POTS (plain old telephone set) is still alive.
Figure 1. Proposed solutions for the subscriber
Central office
Long line
Pots
Suscriber house
Pots
Short line
High speed digital link
High speed to
Pots coupling
Figure 1 shows possibilities subscribers already have got and which will be in a growing
phase in the near future. This will split the SLIC (Subscriber Line Interface Circuit) in two
different types according to the application:
■ The long lines using the classical copper twisted pairs up to several kilometers long
■ The short lines (only a few tens of meter long)
In the second case shown at the bottom of Figure 1, the long distance carrying of the signal
is assumed by modern digital supports like optical fibers, coax, RF link etc.
For both of these applications the protection needs remain one of the major issues of the
system design, so STMicroelectronics, which is one of the major players in the world of
telecom protection, already proposes optimized solutions for these two topologies.
June 2011
Doc ID 10917 Rev 2
1/15
www.st.com