TDA7403_02 Datasheet, PDF (7/25 Pages) STMicroelectronics – BASIC SIGNAL PROCESSOR

TDA7403
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).
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