U4089B-P Datasheet, PDF (2/26 Pages) ATMEL Corporation – Monolithic Integrated Feature Phone Circuit

Figure 1. Simple Block Diagram
Speech
circuit
Voice
switch
Audio
amplifier
Dialer
Figure 2. Block Diagram
4
MIC1
MIC
3
MIC2
1
DTMF
41
TX
TTXA
ACL
27
INLDR
26
INLDT
Acoustical
29 _feedback
TLDR _{28 suppression}
TLDT
25
control
ATAFS
11
SAO
21
TSACL
SACL
23
SAI
22
GSA
GT
44
STO V_L
32
7
600 Ω
IMPSEL AGA IND
20
30 6
SENSE V_B
9
10
V _MP
13
900 Ω
TXA
Impedance
control
Power
supply
33 ^{V M}
GND
8
Transmit
mute
control
AGA
control
Current
supply
I _REF
31
Supply
R-
attenuation
24
MUTX
39
RECO
40
GR
36
STI
42
RECIN
2 U4089B-P
4518A–CORD–05/02