U3900BM
Target Specification
Rev. A2, 25-Aug-98
1 (34)
Programmable Telephone Audio Processor
Description
The programmable telephone audio processor U3900BM
is a linear integrated circuit for use in feature phones,
answering machines, fax machines and cordless phones.
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 signal amplification and
adaptation to the line. The U3900BM can also be supplied
via an external power supply. An integrated voice switch
with loudspeaker amplifier enables hands-free or loud-
hearing operation. With an anti-feedback function,
acoustical feedback during loudhearing can be reduced
significantly. The generated supply voltage is suitable for
a wide range of peripheral circuits.
Features
D Speech circuit with anti-clipping
D Tone ringer interface with DC/DC converter
D Speaker amplifier with anti-distortion
D Power-supply management, regulated, unregulated
and a special supply for electret microphone
D Voice switch
D CLID + SCWID
D DTMF generator
D Switch matrix
D Line current information
D Fully programmable
D Watchdog
Benefits
D Savings of one piezoelectric transducer
D Complete system integration of analog signal
processing on one chip
D Very few external components
D Highly integrated solution
D Extremely versatile due to full programmability
Applications
Feature phone, answering machine, fax machine, speaker
phone, base station of cordless phone
14602
Speech
circuit
Voice
switch
Audio
amplifier
Serial
bus
Class
Clock
Data
Reset
MCU
DTMF
Tone
ringer
Ordering Information
Extended Type Number
Package
Remarks
U3900BM-AFN
SSO44
U3900BM-AFNG3
SSO44
Taped and reeled