U4090B-P Datasheet, PDF (10/35 Pages) ATMEL Corporation – Monolithic Integrated Feature Phone Circuit EMI Improved

Figure 3-4. Basic Voice Switch System
Handset
microphone
TX
Att
Log
Att
contr
Log
Loudspeaker
RX
Att
Hybrid
Line
Figure 3-5. Integration of the Acoustic Feedback Suppression Circuit into the Speech Circuit Environment
VL
GT MICO TIN
INLDT
TLDT
STO VL
Z_L
VBG
-
+
TXA
Zint
SAO
GSA
SAI
SAI TLDR
AFS
control
Max
att.
AGA
-
+
VBG
INLDR
RECO1 GR STIS
RECIN
STN
STO
10 U4090B-P
4741C–CORD–11/05