ST5088

PROGRAMMABLE AUDIO FRONT END

FOR DIGITAL PHONES AND ISDN TERMINALS

FEATURES:

Complete CODEC and FILTER system including:

PCM ANALOG TO DIGITAL AND DIGITAL TO

ANALOG CONVERTERS

POWERFUL ANALOG FRONT END CAPA-

BLE TO INTERFACE DIRECTLY:

- Microphone Dynamic or Electrete

- Earpiece down to 100

Ω or up to 150nF

- Loudspeaker down to 50

Ω or Buzzer up to

600nF.

TRANSMIT BAND-PASS FILTER

ACTIVE RC NOISE FILTER

RECEIVE LOW-PASS FILTER WITH SIN X/X

CORRECTION

MU-LAW OR A-LAW SELECTABLE COM-

PANDING CODER AND DECODER

PRECISION VOLTAGE REFERENCE

Phones Features:

DUAL SWITCHABLE MICROPHONE AMPLI-

FIER INPUTS. GAIN PROGRAMMABLE: 15

dB RANGE, 1 dB STEP.

LOUDSPEAKER AMPLIFIER OUTPUT.

SWITCHABLE MAXIMUM GAIN: +9dB/+27dB

WITH AUTOMATIC DIGITAL ANTICLIPPING

SYSTEM. aTTENUATION PROGRAMMABLE:

30dB RANGE, 2dB STEP.

SEPARATE EARPIECE AMPLIFIER OUTPUT.

ATTENUATION PROGRAMMABLE: 15 dB

RANGE, 1 dB STEP.

AUXILIARY TAPE RECORDER ANALOG IN-

TERFACE: Tx + Rx COMBINED OUTPUT.

AUXILIARY SWITCHABLE EXTERNAL RING

INPUT (EAIN).

TRANSIENT SUPRESSION SIGNAL DURING

POWER ON.

INTERNAL

PROGRAMMABLE

SIDETONE

CIRCUIT. ATTENUATION PROGRAMMABLE:

15 dB RANGE, 1 dB STEP, INDEPENDENT

FROM Rx CONTROL.

INTERNAL RING OR TONE GENERATOR IN-

CLUDING DTMF TONES, SINEWAVE OR

SQUAREWAVE

WAVEFORMS.

ATTENU-

ATION PROGRAMMABLE: 27 dB RANGE, 3

dB STEP.

RINGER CONTROL PROGRAMMABLE IN-

TERNALLY (

µP) OR EXTERNALLY (pin AT)

COMPATIBLE WITH HANDS-FREE CIRCUIT

TEA7540.

ON CHIP SWITCHABLE ANTI-ACOUSTIC

FEED-BACK CIRCUIT (ANTI-LARSEN).

General Features:

EXTENDED TEMPERATURE RANGE OP-

ERATION (*) –25

°C TO +85°C.

EXTENDED POWER SUPPLY RANGE 5V

±10%.

60 mW OPERATING POWER (TYPICAL).

1.0 mW STANDBY POWER (TYPICAL).

CMOS DIGITAL INTERFACES.

SINGLE + 5V SUPPLY.

DIGITAL LOOPBACK TEST MODE.

PROGRAMMABLE DIGITAL AND CONTROL

INTERFACES:

– Digital PCM Interface associated with

separate

serial

Control

Interface

MI-

CROWIRE

™ compatible.

– GCI interface compatible.

(*) Functionality guaranteed in the range – 25

°C to +85°C;

Timing and Electrical Specifications are guaranteed in the range

–5

°C to +70°C.

APPLICATIONS:

ISDN TERMINALS.

DIGITAL TELEPHONES

CT2 AND GSM APPLICATIONS

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

December 1999

®

ORDERING NUMBERS:

ST5088D

ST5088FN

PLCC28

SO28

1/33