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TDA8295_09 Datasheet, PDF (34/83 Pages) NXP Semiconductors – Digital global standard low IF demodulator for analog TV and FM radio | |||
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NXP Semiconductors
TDA8295
Digital global standard low IF demodulator for analog TV and FM radio
9.3.9 Tuner IF AGC functions
Table 29. T_IF_AGC_SET register (address 15h) bit description
Legend: * = default value.
Bit Symbol
Access Value
Description
7
POL_TIF
R/W
tuner IF AGC polarity
0
inverted tuner IF AGC polarity
1*
normal tuner IF AGC polarity: the higher
the necessary gain, the higher the IF
AGC voltage
6 to 0 T_IF_AGC_SPEED[6:0] R/W
T_IF_AGC_SPEED determines the tuner
IF AGC loop speed
000 0001 â18 dB nominal
000 0010 â12 dB nominal
000 0100 â6 dB nominal
000 1000* nominal speed (determined by the tuner
IF control slope)
001 0000 +6 dB nominal
010 0000 +12 dB nominal
100 0000 +18 dB nominal
Table 30. T_IF_AGC_LIM register (address 16h) bit description
Legend: * = default value.
Bit Symbol
Access Value Description
7 to 4 UP_LIM[3:0] R/W
The tuner IF AGC output voltage can be limited to
interface with concepts having power supply < 3.3 V.
UP_LIM determines the upper limit from 1â2 FS (= 0h) to
FS (= Fh). The format is straight binary.
1111* set upper limit to maximum
3 to 0 LOW_LIM[3:0] R/W
LOW_LIM determines the lower tuner IF AGC output
limit from 0 (= 0h) to 1â2 FS (= Fh). The format is straight
binary.
0000* set lower limit to minimum
TDA8295_C2_2
Product data sheet
Table 31. T_IF_AGC_FORCE register (address 17h) bit description
Legend: * = default value.
Bit Symbol
Access Value Description
7
T_FORCE
R/W
the tuner IF AGC output voltage can be forced
externally to a fixed voltage, determined by
T_FORCE_VAL
0*
tuner IF AGC normal operation
1
tuner IF AGC output voltage determined by
T_FORCE_VAL
6 to 0 T_FORCE_VAL[6:0] R/W
T_FORCE_VAL determines the tuner IF AGC
forced value. So the tuner IF AGC can be fixed to
a certain value for debugging purposes. Format is
straight binary.
3Fh*
XXh
0.5 Ã VDD(3V3), i.e. 1.65 V nominally
donât care if T_FORCE = 0
Rev. 02 â 27 November 2009
© NXP B.V. 2009. All rights reserved.
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