PHILIPS TEA1085; TEA1085A Listening-in circuit for line-powered telephone sets handbook

TEA1085 and TEA1085A are bipolar ICs which have been designed for use in line-powered telephone sets and provide a listening-in facility for the received line signal via a loudspeaker. Nearly all the line current can be used for powering the loudspeaker. The circuits incorporate a supply circuit, loudspeaker amplifier dynamic limiter, MUTE circuit, power-down facility and logic inputs for gain setting.

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