STA323W datasheet(55/71 Pages) STMICROELECTRONICS

55 / 71 page

STA323W

55/71

The release of limiter, when the gain is again increased, is dependent on an RMS-detect

algorithm. The output of the volume limiter block is passed through an RMS filter. The output

of this filter is compared with the release threshold, determined by the Release Threshold

When the RMS filter output falls below the release threshold, the gain is increased at a rate

dependent upon the release rate register. The gain can never be increased past its set value

and therefore the release will only occur if the limiter has already reduced the gain. The

release threshold value can be used to set what is effectively a minimum dynamic range.

This is helpful as over-limiting can reduce the dynamic range to virtually zero and cause

program material to sound “lifeless”.

In AC mode the attack and release thresholds are set relative to full-scale. In DRC mode the

attack threshold is set relative to the maximum volume setting of the channels mapped to

that limiter and the release threshold is set relative to the maximum volume setting plus the

attack threshold.

Figure 50.

Basic limiter and volume flow diagram

Table 63.

Limiter attack rate selection

LxA (3...0)

Attack rate dB/ms

0000

3.1584

Fast

0001

2.7072

0010

2.2560

0011

1.8048

0100

1.3536

0101

0.9024

0110

0.4512

0111

0.2256

1000

0.1504

1001

0.1123

1010

0.0902

1011

0.0752

1100

0.0645

1101

0.0564

Gain

Attenuation

Saturation

Output

Input

Gain/volume

Limiter

RMS

STA323W Datasheet(PDF) 55 Page - STMicroelectronics

STA323W Datasheet(HTML) 55 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71

Datasheet Download

Link URL