TDA7703 Datasheet, PDF (22/32 Pages) STMicroelectronics – Automatic self alignment for image rejection

Front-end processing
4
Front-end processing
TDA7703
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
(Communication Protocol manual).
Table 16. 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 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
90 dBµV
001
91 dBµV
010
92 dBµV
011
93 dBµV
100
90 dBµV
101
89 dBµV
110
88 dBµV
111
87 dBµV
AM AGC attack time constant
0
normal
1
fast
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Rev 1