TDA7409 ST Microelectronics, TDA7409 Datasheet - Page 11

• Manufacturer Part Number: TDA7409
• Description: CARRADIO-SIGNAL-PROCESSOR
• Manufacturer: ST Microelectronics

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
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
dB
-10.0
-15.0
15.0
10.0
-5.0
5.0
0.0
10.0
V o u t
- 1 d B
- 2 d B
2 d B
1 d B
100.0
S S T i m e
Hz
1.0K
10.0K
T i m e
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