TDA7407_07 Datasheet, PDF (22/46 Pages) STMicroelectronics – Advanced car signal processor

Multipath detector
TDA7407
5.1.6
Softmute
The digitally controlled softmute stage allows muting/demuting the signal with a I²C bus
programmable slope. The mute process can either be activated by the softmute pin or by the
I²C bus. The slope is realized in a special S shaped curve to mute slow in the critical
regions.
Figure 7. Input stages
CD+
1
100K
CD-
1
100K
PHONE+
PHONE-
CASSETTE
AM
MPX
100K
100K
100K
15K
15K
15K
+
-
15K
27K
27K
28K
+
-
28K
STEREO DECODER
CD OUT
IN GAIN
D98AU854A
Figure 8. Softmute timing
Note:
5.1.7
1
EXT.
MUTE
+SIGNAL
REF
-SIGNAL
1
I²C BUS
OUT
D97AU634
Time
Please notice that a started Mute action is always terminated and could not be interrupted
by a change of the mute signal.
For timing purposes the Bit 3 of the I²C bus output register is set to 1 from the start of muting
until the end of demuting.
BASS
There are four parameters programmable in the bass stage: (see figs 9, 10, 11, 12):
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