ST952

D.A.A. LINE INTERFACE

December 1998

PRELIMINARY DATA

.

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

This is advance information on a new product now in development or undergoing evaluation. Details are subject to change without notice.

DESCRIPTION

ST952 is a line interface designed to implement

Modem application up to 56Kbps and Voice appli-

cations.

ST952 interfaces between telephone line and ca-

pacitive isolation barrier.

A complete D.A.A. is made with ST75951 which

interfaces between capacitive isolation barrier and

the DSP or HSP signals.

10

11

12

13

14

15

18

19

20

21

22

4

3

2

1

25 26 27 28 29

23

16

24

30 31 32

8

7

6

5

9

LIM1

LIM2

TOFF

D6

D5

RIN

D4

D3

17

TER1

SET

VDR

LINE

IDG

IDI

LINI

GAIN

PIN CONNECTIONS

ST75951

ST952

Digital

Signals

Tip

Ring

It incorporates Krypton Isolation Inc. patented sili-

con DAA technology.

The ring burst signal is detected by ST952 and is sent

to ST75951 through the capacitive isolation barrier.

Using the control signals given by ST75951, through

the capacitive isolation barrier, ST952 activates the

off-hook or the CLID external transistor switch.

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 ca-

pacitive 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.

TQFP32 (7 x 7 x 1.4mm)

(Thin Plastic Quad Flat Pack)

ORDER CODE : ST952TQF7

1/12