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