sta381bws STMicroelectronics, sta381bws Datasheet - Page 29

• Manufacturer Part Number: sta381bws
• Description: Sound Terminal 2.1-channel High-efficiency Digital Audio System Sound Terminal 2.1-channel High-efficiency Digital Audio System
• Manufacturer: STMicroelectronics

STA381BWS
4.3.1
Caution:
4.3.2
STC block diagram
Figure 8.
The STC takes as input 2 channels and every channel is processed independently (i.e. an
independent DRC for each band of each channel) following the steps listed below
(Figure
1.
2.
3.
4.
The band splitter settings are common to both the processing channels while the settings of
the remaining blocks can be independently set for each band of each processing channel.
All the settings explained hereafter apply only to the behavior of the STCompressor
the settings concerning other device operating configurations (see
data
Band splitter
The band splitter block is used to divide the signal into 2 sub-bands (typically low and high
frequency bands). This is done through two 2
thus allowing to have up to a 4
band recombination (see
negligible gain around the filters cutoff frequency, endangering the overall audio fidelity and,
eventually, also the safety of the speaker. The sub-band recombination can be enabled or
disabled.
In p ut
In p ut
Ch 0
Ch 1
Splits the input signal into 2 bands (band splitter)
Measures the level of the signal (level meter)
Computes the attenuation (mapper)
Applies the attenuation and offset (attenuator)
path) please refer to the appropriate paragraphs and registers.
8):
Sp litter
Sp litter
Ban d
Ban d
STCompressor
(Lo w freq s)
(Hig h freq s)
(Lo w freq s)
(Hig h freq s)
Ban d 0
Ban d 1
Ban d 0
Ban d 1
Figure
TM
Doc ID 018937 Rev 2
Meter
Meter
th
Meter
Meter
Level
Level
Level
Level
block diagram
9). Using different filtering orders, indeed, causes a non-
order filter per band. This feature guarantees a totally flat
Map p er
Map p er
Map p er
Map p er
nd
DRC 2
DRC 3
DRC 0
DRC 1
order biquads (IIR filters) for each band,
Atten uato r
Atten uato r
Atten uato r
Atten uato r
O ffset
O ffset
O ffset
O ffset
Chapter 4.1: Processing
X
X
X
X
Device overview
+
+
O utp ut
O utp ut
Ch 1
Ch 0
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. For