ISD3900
Publication Release Date: Dec 10, 2013
- 49 -
Revision 1.5
10
62.5
11
125
Table 12-32 CFGD Register
CFGD Configuration Register
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
AGC_IG_EN
AGC_IG[6:0]
Default 0x00:
Disable the AGC initial gain setting. Initial gain the AGC is 0 dB.
Configuration register CFGD controls the functionality of the AGC:
AGC_IG[6:0]
– Allows the initial gain of the AGC to be set. This gain is applied anytime
AGC_IG_EN=1 and AGC_EN=0.
AGC_IG_EN
– Enables the AGC initial gain setting feature. If AGC_IG_EN=0 then initial gain
of the AGC is 0dB. If AGC is activated (AGC_EN=1) then gain will adjust according to the
AGC algorithm. *Note: When AGC is disabled (AGC_EN=0) the last gain will continue to be
applied to the ADC input. To reset the ADC gain back to 0dB user must write AGC_IG=8,
AGC_IE_EN=1.
Table 12-33 AGC Initial Gain
AGC Initial Gain
AGC_IG[6:0]
Gain
Gain (dB)
0
0
1
0.016
-36
8
1
0
n
(n * n)/64
20*log(n*n/64)
120
225
47
127
252
48
Table 12-34 CFGE Register
CFGE Configuration Register
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0
AGC_G[6:0]