DESCRIPTION

ST952 is a line interface designed to implement Modem application up to 56Kbps and Voice applications.

ST952 interfaces between telephone line and capacitive isolation barrier.

A complete D.A.A. is made with ST75951 which interfaces between capacitive isolation barrier and the DSP or HSP signals.

If CLID external transistor switch is enabled, a limited amount of current, less than 1mA, is drawn from the line.

In off-hook state, ST952 DC voltage, 4V at a 20mA line current, allows to interface with most of public networks in the world.

The return loss is externally adjustable to real or complex impedance.

In case of a wrong connection in a digital phone line, ST952 detects the over current value and sends to ST75951 an alert signal through the capacitive isolation barrier.

Before starting a line connection, ST952 is abled to check if the line is used by an other terminal connected on the same telephone line.

■ HOOK SWITCH DRIVER

■ RING INDICATOR

■ LINE INTERFACE

- DC TERMINATION (4V AT 20mA)

- 2W/4W HYBRID CONVERTER

- FLAT FREQUENCY RESPONSE DOWN TO 10Hz FOR 56Kps MODEM

■ INTERFACE WITH CAPACITIVE ISOLATION BARRIER

■ CALLER ID INTERFACE

■ DIGITAL PHONE LINE OR OVER LOOP CURRENT LIMIT DETECT

■ PHONE LINE IN USE CHECK

APPLICATIONS

■ MODEMS UP TO V.34, 33.6KBPS AND 56Kbps

■ PCMCIA CARDS

■ FAX MACHINES

■ PERSONAL DIGITAL ASSISTANTS

■ ANSWERING MACHINES

■ HIGH FEATURE PHONES

■ WEBPHONES AND SET TOP BOXES