TDA7407D Datasheet, PDF (15/34 Pages) STMicroelectronics – ADVANCED CAR SIGNAL PROCESSOR

TDA7407D
6.4 TREBLE
There are two parameters programmable in the treble stage (see figs 17, 18):
6.4.1 Attenuation
Figure 17 shows the attenuation as a function of frequency at a center frequency of 17.5KHz.
6.4.2 Center Frequency
Figure 15 shows the four possible Center Frequency (10, 12.5, 15 and 17.5kHz).
6.4.3 AC Coupling
In some applications additional signal manipulations are desired, for example surround-sound or more-
band-equalizing. For this purpose a AC-Coupling is placed before the Speaker-attenuators, which can be
activated or internally shorted by Bit7 in the Bass/Treble-Configuration byte. In short condition the input-
) signal of the speaker-attenuator is available at AC Outputs and the AC Input could be used as additional
t(s ^{stereo inputs. The input impedance of the AC Inputs is always 50KΩ.}
c _{6.4.4 Speaker Attenuator}
du The speaker attenuators have exactely the same structure and range like the Volume stage.
Pro _t(s) ^{Figure 10. Bass Control @ fc = 80Hz, Q = 1}
te ^c 15.0
sole ^{rodu 10.0}
b ^P _5.0
) ^{- O lete 0.0}
Figure 12. Bass Quality factors @ Gain = 14dB,
fc = 80Hz
15.0
12.5
10.0
7.5
t(s ^{so -5.0}
5.0
uc Ob _-10.0
rod ^{) -} -15.0
P _t(s 10.0
100.0
1.0K
10.0K
2.5
0.0
10.0
100.0
1.0K
10.0K
lete duc ^{Figure 11. Bass Center @ Gain = 14dB, Q = 1}
so ^ro 15.0
Ob _te ^P 12.5
le _10.0
Obso ^7.5
Figure 13. Bass normal and DC Mode @ Gain =
14dB, fc = 80Hz
15.0
12.5
10.0
7.5
5.0
5.0
2.5
0.0
10.0
100.0
1.0K
10.0K
2.5
0.0
10.0
100.0
1.0K
10.0K
Note: In general the center frequency, Q and DC-mode can be set
independently. The exception from this rule is the mode (5/xx1111xx)
where the center frequency is set to 150Hz instead of 100Hz.
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