STA304A STMicroelectronics, STA304A Datasheet - Page 15

• Manufacturer Part Number: STA304A
• Description: IC PROCESSOR AUD DGTL DDX 44TQFP
• Manufacturer: STMicroelectronics
• Series: DDX™r
• Type: Audio Processorr

Specifications of STA304A

• Mounting Type: Surface Mount
• Package / Case: 44-TQFP, 44-VQFP
• Case: QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Applications: -
• Other names: 497-3944

Each channel has a 4 stage cascaded 2nd order filter. The user can set each filter coefficients (see paragraph
10). The coefficient for the Left and Right channels are common, as well as the coefficients for the surrounds.
There is also an input scaling factor for each channel which can be set with values from 0 to -1. The scaling
factor should be set to an appropriate value that will prevent the filter going into saturation.
The Static EQ filters are activated by setting Static EQ and Side Firing register (add. 70h, see section 12.12).
9.3 Surround Side Firing
Instead of the normal filters described in the previous section above, a special topology is available for the sur-
round channels:
Figure 10.
By designing appropriate filters special surround sound can be achieved for a system which its surround speak-
ers are located next to the front speakers and are rotated to the sides (see picture). The Side firing topology is
enabled by setting Static EQ and Side Firing register (add. 70h, see section 12.12).
Figure 11. Speaker System with Side-Firing positioning
Right Surround
Left Surround
Input
Input
Scale in
Scale in
Factor
Factor
bi-quad0
bi-quad2
bi-quad0
bi-quad2
bi-quad1
bi-quad3
bi-quad1
bi-quad3
+
and Phase
Invering
+
Right Surround
Left Surround
Output
Output
STA304A
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