SLOS524D – JUNE 2008 – REVISED AUGUST 2009........................................................................................................................................................ www.ti.com
AGC CONTROL (Address: 6)
REGISTER
I2C
LABEL
DEFAULT
DESCRIPTION
ADDRESS
BIT
06 (06H) –
7
Output Limiter
0 (enable)
Disables the output limiter function. Can only be disabled when the AGC
AGC Control
Disable
compression ratio is 1:1 (off)
6:5
NoiseGate
01 (4mVrms)
Select the threshold of the noise gate
Threshold
00
1 mVrms
01
4 mVrms
10
10 mVrms
11
20 mVrms
4:0
Output Limiter
11010 (6.5dBV)
Selects the output limiter level
Level
Output Power
Peak Output
dBV
(Wrms)
Voltage (Vp)
00000
0.03
0.67
–6.5
00001
0.03
0.71
–6
00010
0.04
0.75
–5.5
(Limiter level increases by 0.5dB with every step)
11101
0.79
3.55
8
11110
0.88
3.76
8.5
11111
0.99
3.99
9
Output Limiter
This bit disables the output limiter function when set to 1. Can only be disabled when
Disable
the AGC compression ratio is 1:1
NoiseGate Threshold
These bits set the threshold level of the noise gate. NoiseGate Threshold is only
functional when the compression ratio is not 1:1
Output Limiter Level
These bits select the output limiter level. Output Power numbers are for 8
load.
AGC CONTROL (Address: 7)
REGISTER
I2C
LABEL
DEFAULT
DESCRIPTION
ADDRESS
BIT
07 (07H) –
7:4
Max Gain
1100 (30 dB)
Selects the maximum gain the AGC can achieve
AGC Control
Gain
0000
18 dB
0001
19 dB
0010
20 dB
(gain increases by 1 dB with every step)
1100
30 dB
3:2
Unused
00
1:0
Compression
10 (4:1)
Selects the compression ratio of the AGC
Ratio
00
1:1 (off)
01
2:1
10
4:1
11
8:1
Compression Ratio These bits select the compression ratio. Output Limiter is enabled by default when the
compression ratio is not 1:1.
Max Gain
These bits select the maximum gain of the amplifier. In order to maximize the use of the
AGC, set the Max Gain to 30dB
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