STA308 STMicroelectronics, STA308 Datasheet - Page 22

• Manufacturer Part Number: STA308
• Description: IC AUDIO PROCESSOR DGTL 64-TQFP
• Manufacturer: STMicroelectronics
• Series: DDX™r
• Type: Audio Processorr

Specifications of STA308

• Mounting Type: Surface Mount
• Package / Case: 64-TQFP, 64-VQFP
• Case: QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Applications: -

STA308
3.23 Limiter 1 Attack/Release Rate (address 17h)
3.24 Limiter 1 Attack/Release Threshold (address 18h)
3.25 Limiter 2 Attack/Release Rate (address 19h)
3.26 Limiter 2 Attack/Release Threshold (address 1Ah)
Basic Limiter and Volume Flow Diagram.
A limiter is basically a variable gain device, where the amount of gain applied depends on the input signal level.
As the name implies, compression limits the dynamic range of the signal.
The STA308 includes 2 independent limiter blocks.
The purpose of the limiters is to automatically reduce the dynamic range of the input signal to prevent the out-
puts from clipping in anti-clipping mode or to actively reduce the dynamic range for a better listening environ-
ment such as a night-time listening mode which is often needed for DVDs. The two modes are selected via the
DRC bit in Configuration Register B; address 0x02, bit 7.
Each channel can be mapped to either limiter or not mapped. Non-mapped channels will clip when 0dBFS is
exceeded. Each limiter will look at the present value of each channel that is mapped to it, select the maximum
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NAME
NAME
NAME
NAME
RST
RST
RST
RST
BIT
BIT
BIT
BIT
Gain/Volume
Input
L1AT3
L2AT3
L1R3
L2R3
D7
D7
D7
D7
1
0
1
0
L1AT2
L2AT2
L1R2
L2R2
D6
D6
D6
D6
Gain
0
1
0
1
L1AT1
L2AT1
L1R1
L2R1
D5
D5
D5
D5
1
1
1
1
Attenuation
Limiter
L1AT0
L2AT0
L1R0
L2R0
D4
D4
D4
D4
0
0
0
0
L1RT3
L2RT3
L1A3
L2A3
D3
D3
D3
D3
0
0
0
0
Saturation
RMS
L1RT2
L2RT2
L1A2
L2A2
D2
D2
D2
D2
1
1
1
1
L1RT1
L2RT1
L1A1
L2A1
D1
D1
D1
D1
1
1
1
1
Output
L1RT0
L2RT0
L1A0
L2A0
D0
D0
D0
D0
0
1
0
1