TDA7403 datasheet(7/25 Pages) STMICROELECTRONICS

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Softstep Volume

When volume level is changed often an audible

click appears at the output. The root cause of

those clicks could be either a DC offset before

the volume stage or the sudden change of the

envelope of the audio signal. With the Softstep

feature both kinds of clicks could be reduced to a

minimum and are no more audible (see figure 3).

Bass

There are three parameters programmable in the

bass stage (see figs 4, 5, 6, 7):

- Attenuation

- Center Frequency (60, 70, 80 and 100Hz)

- Quality Factors (1, 1.25, 1.5 and 2)

DC Mode

In this mode the DC gain is increased by 4.4dB.

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 8, 9):

- Attenuation

- Center Frequency (10, 12.5, 15 and 17.5kHz).

Speaker Attenuator

Due to practical aspects the steps in the speaker

attenuators are not linear over the full range. At

attenuations more than 24dB the steps increase

from 1.5dB to 10dB (please see data byte specifi-

cation).

TDA7403

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