Data Sheet

FSC-BT806BDatasheet
Shenzhen Feasycom Technology Co.,Ltdwww.feasycom.com
-25-
DAC Digital Gain
A digital gain stage inside the DAC varies from -24dB to 21.5dB, see following table.There is also a fine gain interface
with a 9-bit gain setting enabling gain changes in 1/32 steps, for more information contact CSR.
The overall gain control of the DAC is controlled by the firmware. Its setting is a combined function of the digital
and analogue amplifier settings.
Table 8: DAC Digital Gain Rate Selection
Digital Gain Selection
Value
DAC Digital Gain Setting(dB)
Digital Gain Selection
Value
DAC Digital Gain Setting(dB)
0
0
8
-24
1
3.5
9
-20.5
2
6
10
-18
3
9.5
11
-14.5
4
12
12
-12
5
15.5
13
-8.5
6
18
14
-6
7
21.5
15
-2.5
DAC Analogue Gain
The following table shows that the DAC analogue gain stage consists of 8 gain selection values that represent
seven 3dBsteps.
The firmware controls the overall gain control of the DAC. Its setting is a combined function of the digital and
analogue amplifier settings.
Table 9: DAC Analogue Gain Rate Selection
Analogue Gain Selection
Value
DAC Analogue Gain
Setting(dB)
Analogue Gain Selection
Value
DAC Analogue Gain
Setting(dB)
7
0
3
-12
6
-3
2
-15
5
-6
1
-18
4
-9
0
-21
DAC Digital FIR Filter
The DAC contains an integrated digital FIR filter with the following modes:
A default long FIR filter for best performance at >= 44.1kHz.
A short FIR to reduce latency.
A narrow FIR (a very sharp roll-off at Nyquist) for G.722 compliance. Best for 8kHz / 16kHz.