TEA7091

TELEPHONE ANALOG FRONT END

PRODUCT PREVIEW

FEATURES:

SPEECH

DC LINE CURRENT RANGE FROM 6 TO

110mA

Tx AND Rx GAIN EXTERNALLY ADJUST-

ABLE

AGC IN Tx AND Rx EXTERNALLY PRO-

GRAMMABLE

AGC DISABLEABLE THROUGH MICROCON-

TROLLER BUS

SINGLE/DOUBLE

SIDETONE

NETWORK

SOFTWARE PROGRAMMABLE

SOFTCLIPPING ON Tx CHANNEL

SQUELCH TO REDUCE Tx NOISE ENVI-

ROMENT AND TO IMPROVE HOWLING IM-

MUNITY 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 FEED-

BACK SYSTEM COUPLED WITH SQUELCH

DIGITAL VOLUME CONTROL (8 STEPS OF

4dB EACH) THROUGH MICROCONTROL-

LER BUS

ANTILARSEN ATTENUATION (4 DIFFERENT

LEVELS) PROGRAMMABLE THROUGH MI-

CROCONTROLLER BUS

HANDSFREE INTERFACE

PIN AND SOFTWARE FACILITY FOR EASY

INTERCONNECTION

WITH

HANDSFREE

CONTROLLER IC.

RING ON LOUDSPEAKER

EMBEDDED SWITCH MODE POWER SUP-

PLY TO FEED THE LOUDSPEAKER AMPLI-

FIER DURING RING MODE

DIGITAL VOLUME CONTROL (8 STEPS OF

4dB EACH) THROUGH MICROCONTROL-

LER BUS

RING

FREQUENCY

GENERATOR

PRO-

GRAMMED

THROUGH

MICROCONTROL-

LER BUS

DIALLING

DTMF

GENERATOR

(CONTROLLED

BY

MCU BUS)

DC MASK VALUE DURING MAKE PERIOD

PROGRAMMABLE THROUGH MICROCON-

TROLLER BUS

MICROCONTROLLER INTERFACE

STABILIZED VOLTAGE FOR MICROCON-

TROLLER

2 WIRE SERIAL BUS

RING INDICATOR

POWER-ON SIGNAL

RESET SIGNAL

LINE CURRENT VARIATION INDICATOR

SELF BIASED LOUDSPEAKER AMPLIFIER FOR

ANSWERING MACHINE

This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice.

September 1993

PLCC44

PQFP44

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