TA0313 Datasheet, PDF (1/9 Pages) STMicroelectronics – STMicroelectronics Solutions for ADSL Line Interfaces

TA0313
Technical Article
STMicroelectronics Solutions for
ADSL Line Interfaces
This paper describes STMicroelectronics ADSL analog line interface solutions.
New IGBT Driver
After a short overview of the ADSL application environment, this article focuses on the implementation of
line drivers. Magnetic circuits such as hybrid or line transformer circuits will not be described in detail.
The ADSL concept
Asymmetric Digital Subscriber Line (ADSL) is a modem technology, which converts existing twisted-pair
telephone lines into access paths for multimedia and high speed data communications.
An ADSL modem is connected to a twisted-pair telephone line, creating three information channels: a
high-speed downstream channel (up to 1.1MHz and 2.2MHz for ADSL2+) depending on the
implementation of the ADSL architecture, a medium-speed upstream channel (up to 135kHz or 230kHz)
and a POTS (Plain Old Telephone Service), split off from the modem by filters.
Figure 1: Typical spectral representation of a DMT ADSL signal (subscriber side)
Upstream
Downstream
DMT sub-channel
(Discrete Multi-Tone)
POTS
4.5kHz 30kHz 135kHz 160kHz
1.1MHz
ADSL allows the wide-band access necessary to transmit media such as movies, television, remote CD-
ROMs via LANs and the Internet into individual workplaces and homes.
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