U4055B Datasheet, PDF (1/10 Pages) TEMIC Semiconductors – Low-Voltage Electronic Speech Circuit with Dialer Interface

U4055B/U4055B1
Low-Voltage Electronic Speech Circuit with Dialer Interface
Description
The U4055B electronic speech circuit is a linear
integrated circuit for use in telephone and other line fed
terminal equipment. It replaces the common speech
circuit with carbon microphone, hybrid transformer,
sidetone equivalent and ear protection rectifiers. A
low-cost electrodynamic transducer is used as the
earphone. It contains all components necessary for
amplification of signals and adaption to the line.
Features
D An electronic circuit replaces the microphone hybrid
transformer
D Symmetrical input for dynamic or piezo microphone
D High performance through the use of dynamic
xtransducers as the earphone (non-linear distortion
2 %)
D Automatic line loss compensation
D DTMF interface with muting
D Supply voltage for dialer
D High range of line feeding current
D Input resistance independent of line current and
sidetone suppression circuit.
D Built-in ear protection by earphone voltage limiter
D Operation possible from 8 mA
U4055B1: High level mute; U4055B: Low level mute
Figure 1. Block diagram and pin connection
TELEFUNKEN Semiconductors
Rev. A1, 06-May-96
Preliminary Information
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