TELEFUNKEN Semiconductors
U4092B
Monolithic Integrated Feature Phone Circuit
Description
The
µc
controlled telephone circuit U4092B 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 and adaptation to the line.
An integrated voice switch with loudspeaker amplifier
allows loudhearing or handsfree operation. With an
anti-feedback function, acoustical feedback during loud-
hearing can be reduced significantly. The generated supply
voltage is suitable for a wide range of peripheral circuits.
Features
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
Built-in ear protection
DTMF and MUTE input
Adjustable sidetone suppression independent
of sending and receiving amplification
Integrated amplifier for loudhearing operation
Anti-clipping for loudspeaker amplifier
Improved acoustical feedback suppression
Power down
Voice switch
Tone ringer interface with dc/dc converter
D
Zero crossing detection
D
Common speaker for loudhearing and tone ringer
D
Supply voltages for all functional blocks of a subscriber
set
D
Integrated transistor for short circuiting the line voltage
D
Answering machine interface
D
Operation possible from 10 mA line currents
Benefits
D
Savings of one piezo electric transducer
D
Complete system integration of analog signal
processing on one chip
D
Very few external components
Applications
Feature phone, answering machine, fax machine, speaker
phone
Speech
circuit
Voice
switch
Audio
amplifier
Loudhearing
and
Tone ringing
MC with
EEPROM/
DTMF
94 8741
Tone
ringer
Rev. A1: 24.01.1995
Preliminary Information
1
TEMIC [ TEMIC SEMICONDUCTORS ]
