Datasheet

3−36
SAP
Input
Port
Resolution
1
6
B
i
t
1
8
B
i
t
2
0
B
i
t
2
4
B
i
t
3
2
B
i
t
48-Bit
DAP
Word
40
39
0
8
7
Headroom
1
6
B
i
t
1
8
B
i
t
2
0
B
i
t
2
4
B
i
t
3
2
B
i
t
48-Bit
DAP
Word
47
44
43
0
8
7
16
DRC
Channel 1
Processing
Resolution
Headroom
2
4
Channel 2
Processing
0-dB Gain
0-dB Gain
2
4
47
Figure 3−22. DRC Input Word Structure for 0-dB Channel Processing Gain
The resulting DRC transfer function for the above parameters is shown in Figure 3−23. The threshold T2 is set at the
DRC rms input level of −50 dB, which corresponds to a −26-dB rms signal level at the SAP input. The
DRC-compensated output at T2 is cut 30 dB with respect to the 1:1 transfer function (O2 = 30 dB). The threshold T1
is set at the DRC rms input level of −125 dB, which corresponds to a −101-dB rms signal level at the SAP input. The
DRC-compensated output at T1 is boosted by 7.5 dB with respect to the 1:1 transfer function (O1 = −7.5 dB).
For thresholds, T
dB
= -6.0206T
INPUT
= -6.0206T
SUB_ADDRESS_ENTRY
.
Therefore,
T2 = −26 dB −24 dB = −50 dB ≥ T2
INPUT
= −50/−6.0206 = 8.30482
= 01000.0100_1110_0000_1000_1010_111
= 0x000004270457 in 25.23 format
T1 = −101 dB −24 dB = −125 dB ≥ T1
INPUT
= −125/−6.0206 = 20.76205
= 010100.1100_0011_0001_0101_1011_010
= 0x00000A618ADA in 25/23 format
For offsets, O
INPUT
+
1
6.0206
ƪ
O
dB
) 24.0824
ƫ
.
Therefore, O2
INPUT
+
1
6.0206
[
30 ) 24.0824
]
+ 8.982892
+ 01000.1111_1011_1001_1110_1100_111
+ 0x0000047DCF67 in 25.23 format