GENERAL DESCRIPTION
ST5088 PIAFE is a combined PCM CODEC/FILTER device optimized for ISDN Terminals and Digital 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 systemincluding:
■ PCM ANALOG TO DIGITAL AND DIGITAL TO ANALOG CONVERTERS
■ POWERFUL ANALOG FRONT END CAPABLE TO INTERFACE DIRECTLY:
    - Microphone Dynamic or Electrete
    - Earpiece down to 100Ω or up to 150nF
    - Loudspeakerdown to 50Ω 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 COMPANDING CODER AND DECODER
■ PRECISION VOLTAGE REFERENCE

Phones Features:
■ DUAL SWITCHABLE MICROPHONE AMPLIFIER 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 INTERFACE: 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 INCLUDING DTMF TONES, SINEWAVE OR SQUAREWAVE WAVEFORMS. ATTENUATION PROGRAMMABLE: 27 dB RANGE, 3 dB STEP.
■ RINGER CONTROL PROGRAMMABLE INTERNALLY (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 OPERATION (*) – 25°C TO +85°C.
■ EXTENDED POWERSUPPLYRANGE 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 MICROWIRE™ compatible.
    –GCI interface compatible.

APPLICATIONS:
■ ISDN TERMINALS.
■ DIGITAL TELEPHONES
■ CT2 AND GSM APPLICATIONS