U4090B - TEMIC Semiconductors

U4090B Monolithic Integrated Feature Phone Circuit

The µc controlled telephone circuit U4090B is a linear integrated circuit for use in feature phones, answering machines and fax machines. It contains the speech circuit, tone ringer interface with dc/dc converter, sidetone equivalent and ear protection rectifiers. The circuit is line powered and contains all components necessary for amplification of signals .

Features

D D D D D D D D D D D D D D D DC characteristic adjustable Transmit and receive gain adjustable Symmetrical input of microphone amplifier Anti-clipping in transmit direction Automatic line loss compensation Symmetrical output of earpiece amplifier Built-in ear protection DTMF and MUTE input Adjustable sidetone suppression independent of sending and receiving amplification Speech circuit with two sidetone networks Built-in line detection circuit Integrated amplifier for loudhearing operation Anti-clipping for loudspeaker amplifier Improved acoustical feedback suppression Power down D Voice swi.