TDA8295_09 Datasheet, PDF (33/83 Pages) NXP Semiconductors – Digital global standard low IF demodulator for analog TV and FM radio

NXP Semiconductors
TDA8295
Digital global standard low IF demodulator for analog TV and FM radio
Table 27. D_IF_AGC_SET_2 register (address 13h) bit description
Legend: * = default value.
Bit Symbol
Access Value
Description
7
D_AGC_ERR_LIM R/W
With D_AGC_ERR_LIM the digital IF AGC
error slope is limited. This can improve
performance under the presence of e.g.
impulsive noise that can confuse the AGC
detector.
0
limitation off
1*
limitation on
6 to 0 D_IF_AGC_BW[6:0] R/W
digital IF AGC 3 dB-loop bandwidth setting
000 0001 25 Hz
000 0010 50 Hz
000 0100 100 Hz
000 1000 200 Hz
001 0000* 400 Hz
010 0000 800 Hz
100 0000 1.6 kHz
Table 28. D_IF_AGC_FORCE register (address 14h) bit description
Legend: * = default value.
Bit Symbol
Access Value Description
7
D_FORCE
R/W
the IF AGC output voltage can be forced externally
to a fixed voltage, determined by IF_AGC_EXT
0*
IF AGC normal operation
1
IF AGC output voltage determined by
D_FORCE_VAL
6 to 0 D_FORCE_VAL[6:0] R/W
This determines the digital IF AGC forced value
and is a ‘don’t care’ if D_FORCE is LOW. The
format is twos complement. The default is 67h,
which equals 0 dB internal gain. In the following
some possible settings for 6 dB gain steps are
shown.
51h
−12 dB
5Ch −6 dB
67h* 0 dB
72h
+6 dB
7Dh +12 dB
08h
+18 dB
13h
+24 dB
1Eh +30 dB
29h
+36 dB
34h
+42 dB
3Fh
+48 dB
XXh don’t care if D_FORCE = 0
TDA8295_C2_2
Product data sheet
Rev. 02 — 27 November 2009
© NXP B.V. 2009. All rights reserved.
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