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U3500BM Datasheet, PDF (1/17 Pages) TEMIC Semiconductors – Cordless Telephone Signal Processor
Cordless Telephone Signal Processor
U3500BM
Description
The programmable cordless phone signal processor
includes all necessary low frequency parts such as
microphone- and earphone amplifier, compander, pre-
emphasis, deemphasis, scrambler, data management,
power-supply management, as well as RF receiving parts
such as IF converter, FM demodulator. RSSI and low
noise amplifier.
Several gains and mutes in transmit and receive direction
are controlled by serial bus while compander, pre- and
deemphasis and scrambler can be bypassed.
Features
RF Receiver Part
D Low-noise amplifier
D IF converter
D FM demodulator
D RSSI
Low Frequency Part
D Symmetrical input of microphone amplifier
D Symmetrical output of earpiece amplifier
Block Diagram
MIXO IFIN1 IFIN2
D Compander
D Pre- and deemphasis
D Scrambler
D Data management
D Power-supply management
D Serial bus
Application: CT0
DACO
MIXIN
MIXGND
LOIN
LNAIN
RGND
LNAO
VBATT
C
D
Oscillator
11.15 MHz
LNA
IFAMP
LOG
Demodulator
RGAIN
ADJ
LPF
LPF
Deem
Divider
D/A
Scrambler
frequency
Expander
LPF
REC
MIC
Serial
Bus
Battery low
detector
LPF
Scrambler
frequency
LPF
TGAIN
ADJ.2
Limiter
Preem
TGAIN
ADJ.1
Compressor
RXO
ETC
EXIN
RECO2
RECO1
MIC1
MIC2
MICO
RXDAT
TXDAT
COIN
VCC TXO
GND
Figure 1. Block diagram
CTC 14678
Rev. A3, 20-May-98
1 (17)
Preliminary Information