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