TDA7705 Datasheet, PDF (30/42 Pages) STMicroelectronics – Single 5 V supply

Front-end processing
4
Front-end processing
TDA7705
All the parameters in this section refer to the programmability of the FE part of the device
(registers). The part of the registers that are not described here have either fixed values or
values written by the tuner drivers, and are described in the proper technical documentation.
Table 22. Register 0x00
Register number
MSB
LSB
Register definition
23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
AM mixer input selector
0 1 input #1
1 0 input #2
AM PIN diode
0
internal
1
external
AM AGC mode
0
LNA and PIN diode
1
PIN diode only
AM AGC time constant
00
slow (125 ms with 1 µF)
01
medium (25 ms with 1 µF)
11
fast (5 ms with 1 µF)
AM AGC threshold @ mixin
000
001
010
011
100
101
110
111
0
1
90 dBµV
91 dBµV
92 dBµV
93 dBµV
90 dBµV
89 dBµV
88 dBµV
87 dBµV
AM AGC attack time constant
normal
fast
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Doc ID 15938 Rev 9