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