U4090B-P Datasheet, PDF (19/35 Pages) ATMEL Corporation – Monolithic Integrated Feature Phone Circuit EMI Improved

7. U4090B-P Control
Table 7-1. Selection of TX Mute and Line Impedance
Logic Level
0
0 to Z
1 to Z
1
IMPSEL
Line impedance = 600Ω
TXA = on
ES = off
Line impedance = 600Ω
TXA = off
ES = on
Line impedance = 900Ω
TXA = off
ES = on
Line impedance = 900Ω
TXA = on
ES = off
U4090B-P
MODE
Speech
Transmit-mute
Transmit-mute
Speech
Table 7-2. Selection of Earpiece Mute and Answering Machine Mode
Logic Level MUTR
RA2 = on
0
RECATT = on
STIS + STIL = on
0 to Z
RA2 = on
RECATT = off
STIS = on, STIL = off
1 to Z
RA2 = off
RECATT = off
STIS = on, STIL = off
AGA off for STIS
RA2 = off
1
RECATT = on
STIS + STIL = on
MODE
Speech
For answering machine
For answering machine
Speech + earpeace mute
Table 7-3. Selection of Transmit Mute
Logic Level MUTX
MIC 1/2 transmit enabled receive enable
0
AFS = on
AGA = on
TXACL = on
DTMF transmit enabled receive enable
Z
AFS = on
AGA = on
TXACL = on
DTMF transmit enabled
DTMF to receive enable
1
AFS = off
AGA = off
TXACL = off
MODE
Speech
For answering machine
DTMF dialling
19
4741C–CORD–11/05