TDA7402_07 Datasheet, PDF (19/71 Pages) STMicroelectronics – Car radio signal processor

TDA7402
Audioprocessor part
4.3
4.3.1
4.3.2
Pause detector / MUX-output
The pin number 40 (Pause/MUX) is configurable for two different functions:
1. During pause detector OFF this pin is used as a mono output of the main input selector.
This signal is often used to drive a level/equalizer display on the car radio front panel.
2. During pause detector ON the pin is used to define the time constant of the detector by
an external capacitor. The pause detector is driven by the internal stereo decoder
outputs in order to use pauses in the FM signal for alternate frequency jumps. If the
signal level of both stereo decoder channels is outside the programmed voltage
window, the external capacitor is abruptly discharged. Inside the pause condition the
capacitor is slowly recharged by a constant current of 25µA. The pause information is
also available via I²C Bus (see I²C Bus programming).
Loudness
There are four parameters programmable in the loudness stage:
Attenuation
Figure 4 shows the attenuation as a function of frequency at f_P = 400Hz
Figure 4. Loudness attenuation @ f_P = 400Hz.
0.0
-5.0
-10.0
dB
-15.0
-20.0
-25.0
10.0
100.0
1.0K
Hz
10.0K
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