DESCRIPTION
The TEA7091 is a Telephone set Analog Front End (TAFE) interface intended for use in conjunction with a microcontroller.
In this configuration the TEA7091 provides a worldwide mid-range telephone set with loudhearing on board and melody ringer on loudspeaker.
Repertory dialer (memory on MCU) and various features (HOLD, Tone/Pulse, Flash, MUTE, adjustable Ringer and Loudhearing levels..) are programmable by MCU.

FEATURES:
SPEECH
■ DC LINE CURRENT RANGE FROM 6 TO 110mA
■ Tx AND Rx GAIN EXTERNALLY ADJUSTABLE
■ AGC IN Tx AND Rx EXTERNALLY PROGRAMMABLE
■ AGC DISABLEABLE THROUGH MICROCONTROLLER BUS
■ SINGLE/DOUBLE SIDETONE NETWORK SOFTWARE PROGRAMMABLE
■ SOFTCLIPPING ON Tx CHANNEL
■ SQUELCH TO REDUCE Tx NOISE ENVIROMENT AND TO IMPROVE HOWLING IMMUNITY IN LOUDHEARING MODE
■ RECEIVING AMPLIFIER FOR PIEZO OR ELECTRODYNAMIC TRANSDUCERS
■ +6dB MODE ON Rx CHANNEL (SELECTABLE THROUGH MICROCONTROLLER BUS)
■ –6dB MODE ON Tx CHANNEL (SELECTABLE THROUGH MICROCONTROLLER BUS)
■ FREQUENCY GENERATOR FOR WAITING MELODY
■ ERROR BEEP GENERATOR
■ HOLD LINE CURRENT DETECTOR FOR TRANSFER/ AUTO RELEASE

GROUP LISTENING / ON-HOOK DIALING
■ ANTI HOWLING WITH ACOUSTIC FEEDBACK SYSTEM COUPLED WITH SQUELCH
■ DIGITAL VOLUME CONTROL (8 STEPS OF 4dB EACH) THROUGH MICROCONTROLLER BUS
■ ANTILARSEN ATTENUATION (4 DIFFERENT LEVELS) PROGRAMMABLE THROUGH MICROCONTROLLER BUS
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