TDA7404D Datasheet, PDF (12/26 Pages) STMicroelectronics – CARRADIO-SIGNAL-PROCESSOR

TDA7404D
1.6 SoftStep-Volume
When the volume-level is changed audible clicks could appear at the output. The root cause of those clicks
could either be a DC-Offset before the volume-stage or the sudden change of the envelope of the audiosignal.
With the SoftStep-feature both kinds of clicks could be reduced to a minimum and are no more audible. Four
programmable soft step time from one step to the next, are user selectable.
Figure 7. SoftStep-Timing
Vout
2dB
1dB
SS Time
-1dB
-2dB
Time
Note: For steps more than 1dB the SoftStep mode should be deactivated because it could generate a 1dB error during the blend-time.
1.7 Bass
There are three parameters programmable in the bass stage:
1.7.1 Attenuation
Figure 8 shows the attenuation as a function of frequency at a center frequency of 80Hz.
Figure 8. Bass Control @ fC = 80Hz, Q = 1
15.0
10.0
5.0
dB
0.0
-5.0
-10.0
-15.0
10.0
100.0
Hz
1.0K
10.0K
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