TDA7402_07 datasheet(19/71 Pages) STMICROELECTRONICS

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TDA7402

Audioprocessor part

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4.3

Pause detector / MUX-output

The pin number 40 (Pause/MUX) is configurable for two different functions:

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.

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).

4.3.1

Loudness

There are four parameters programmable in the loudness stage:

4.3.2

Attenuation

Figure 4 shows the attenuation as a function of frequency at f

P = 400Hz

Figure 4.

Loudness attenuation @ fP = 400Hz.

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

10.0

100.0

1.0K

10.0K

TDA7402 数据表(PDF) 19 Page - STMicroelectronics