GENERAL DESCRIPTION

ST5080A PIAFE is a combined PCM CODEC/FILTER device optimized for ISDN Terminals and Digi tal Telephone applications. This device is A-law and Mu-law selectable and offers a number of programmable functions accessed through a serial control channel.

FEATURES:

Complete CODEC and FILTER system including:

PCM ANALOG TO DIGITAL AND DIGITAL TO ANALOG CONVERTERS

POWERFUL ANALOG FRONT END CAPABLE TO INTERFACE DIRECTLY:

- Microphone Dynamic, Piezo or Electrete

- Earpiece down to 100Ωor up to 150nF

- Loudspeaker down to 50Ωor 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 COMPANDING CODER AND DECODER

PRECISION VOLTAGE REFERENCE

Phones Features:

DUAL SWITCHABLE MICROPHONE AMPLIFIER INPUTS. GAIN PROGRAMMABLE: 15 dB RANGE, 1 dB STEP.

LOUDSPEAKER AMPLIFIER AUXILIARY OUTPUT. ATTENUATION PROGRAMMABLE: 30 dB RANGE, 2 dB STEP.

SEPARATE EARPIECE AMPLIFIER OUTPUT. ATTENUATION PROGRAMMABLE: 15 dB RANGE, 1 dB STEP

AUXILIARY SWITCHABLE EXTERNAL RING INPUT (EAIN).

TRANSIENT SUPRESSION SIGNAL DURING POWER ON.

INTERNAL PROGRAMMABLE SIDETONE

CIRCUIT. ATTENUATION PROGRAMMABLE: 15 dB RANGE, 1 dB STEP.

INTERNAL RING OR TONE GENERATOR IN CLUDING DTMF TONES, SINEWAVE OR SQUAREWAVE WAVEFORMS.

ATTENUATION PROGRAMMABLE: 27 dB RANGE, 3 dB STEP.

COMPATIBLE WITH HANDS-FREE CIRCUIT TEA7540.

ON CHIP SWITCHABLE ANTI-ACOUSTIC FEED-BACK CIRCUIT (ANTI-LARSEN).

APPLICATIONS:

ISDN TERMINALS.

DIGITAL TELEPHONES

CT2 AND GSM APPLICATIONS