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
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