TDA7400D Datasheet, PDF (13/28 Pages) STMicroelectronics – ADVANCED CAR SIGNAL PROCESSOR

TDA7400D
Figure 5. Softmute Timing
1
EXT.
MUTE
+SIGNAL
REF
-SIGNAL
1
I²C BUS
OUT
D97AU634
Time
Note: 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 out-
put register is set to 1 from the start of muting un-
til the end of demuting.
Bass
There are four parameters programmable in the
bass stage: (see figs 6, 7, 8, 9):
Attenuation
Figure 6 shows the attenuation as a function of
frequency at a center frequency at a center fre-
quency of 80Hz.
cies 60,70,80 and 100Hz.
Quality Factors
Figure 8 shows the four possible quality factors 1,
1.25, 1.5 and 2.
DC Mode
In this mode the DC gain is increased by 5.1dB.
In addition the programmed center frequency and
quality factor is decreased by 25% which can be
used to reach alternative center frequencies or
quality factors.
TREBLE
There are two parameters programmable in the
treble stage (see figs 10, 11):
Attenuation
Figure 10 shows the attenuation as a function of
frequency at a center frequency of 17.5KHz.
Center Frequency
Figure 11 shows the four possible Center Fre-
quency (10, 12.5, 15 and 17.5kHz).
Speaker Attenuator
The speaker attenuators have exactely the same
structure and range like the Volume stage.
Central Frequency
Figure 7 shows the four possible center frequen-
Figure 6. Bass Control @ fc = 80Hz, Q = 1
15.0
10.0
5.0
0.0
-5.0
-10.0
-15.0
10.0
100.0
1.0K
10.0K
Figure 7. Bass Center @ Gain = 14dB, Q = 1
15.0
12.5
10.0
7.5
5.0
2.5
0.0
10.0
100.0
1.0K
10.0K
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