DESCRIPTION The TEA7092is a Telephoneset Analog Front End (TAFE) interface intended for use in conjunction with a microcontroller. In this configurationthe TEA7092 provides a worldwide telephone set with loudhearing and melody ringer on loudspeaker.An handsfreetelephoneset can be built by adding the TEA7540 handsfree controller. SPEECH ■ DC LINE CURRENT RANGE FROM 6 TO 120mA ■ EXTERNALLY ADJUSTABLE : - Tx AND Rx GAIN - MAXIMUM TRANSMIT LEVEL - RETURN LOSS - SIDETONE NETWORKS - Tx AND Rx AGC (LINE CURRENT START UP VALUE AND SLOPE) ■ SOFTCLIPPING ON Tx CHANNEL ■ SQUELCHON Tx CHANNEL TO REDUCE NOISE ENVIRONMENT AND TO IMPROVE HOWLING IMMUNITY IN LOUDHEARING MODE ■ RECEIVING AMPLIFIER FOR PIEZO AND ELECTRODYNAMIC TRANSDUCERS ■ FREQUENCY GENERATOR FOR WAITING MELODY ■ ERROR BEEP GENERATOR ■ HOLD LINE CURRENT DETECTOR FOR TRANSFER/AUTO RELEASE FEATURE ■ PROGRAMMABLE BY MICROCONTROLLER SERIAL BUS : - -6dB ON Tx CHANNEL - +6dB ON Rx CHANNEL - AGC INHIBITION ON Tx AND Rx CHANNELS FOR PABX USE - SQUELCH INHIBITION GROUP LISTENING / ON HOOK DIALING ■ ANTI-HOWLING WITH ACOUSTIC FEEDBACK SYSTEM COUPLED TO SQUELCH ■ RING MELODY CONTROL AND ERROR BEEP GENERATORS ■ PROGRAMMABLE BY MICROCONTROLLER SERIAL BUS : - DIGITAL VOLUME CONTROL (7 STEPS OF 4dB EACH) AND OFF MODE HANDFREE INTERFACE ■ PINS AND SOFTWARE FACILITY FOR EASY INTERCONNECTION WITH HANDSFREE CONTROLLER I.C. LIKE TEA7540 RING ON LOUDSPEAKER ■ EMBEDDED SWITCH MODE POWER SUPPLY DRIVER TO FEED THE LOUDSPEAKER AMPLIFIER DURING RING MODE ■ PROGRAMMABLE BY MICROCONTROLLER SERIAL BUS : - DIGITAL VOLUME CONTROL (15 STEPS OF 4dB EACH) AND OFF MODE - RING FREQUENCY GENERATOR (MORE THAN 200 FREQUENCIES AVAILABLE) DIALING ■ PROGRAMMABLE BY MICROCONTROLLER SERIAL BUS : - DTMF GENERATOR - 2V DC LINE VOLTAGE DURING THE MAKE PERIOD IN PULSE MODE MICROCONTROLLER INTERFACE ■ 3.5V STABILIZED SUPPLY ■ TWO WIRES SERIAL BUS INTERFACE ■ RING INDICATOR ■ PON LINE CURRENT INDICATOR ■ RESET SIGNAL ■ LINE CURRENT VARIATION INDICATOR (FOR TRANSFER FEATURE) ■ OSCILLATOR WITH STAND BY MODE CORDLESS AND ANSWERING MACHINE INTERFACE ■ SELF BIASED LOUDSPEAKER AMPLIFIER AND MICROCONTROLLER INTERFACE FOR ANSWERING MACHINE ■ SIGNAL INPUT AND OUTPUT INTERFACE FOR CORDLESS ■ VRMC SUPPLY CAN BE EXTERNALLY FORCED TO 5V FOR EASY INTERFACE WITH A MAIN POWERED MICROCONTROLLER
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