tda8295 NXP Semiconductors, tda8295 Datasheet - Page 32

• Manufacturer Part Number: tda8295
• Description: Tda8295 Digital Global Standard Low If Demodulator For Analog Tv And Fm Radio
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TDA8295_1
Product data sheet
Table 27.
Legend: * = default value.
Table 28.
Legend: * = default value.
Bit
7
6 to 0 D_IF_AGC_BW[6:0] R/W
Bit
7
6 to 0 D_FORCE_VAL[6:0] R/W
Symbol
D_AGC_ERR_LIM
Symbol
D_FORCE
D_IF_AGC_SET_2 register (address 13h) bit description
D_IF_AGC_FORCE register (address 14h) bit description
Digital global standard low IF demodulator for analog TV and FM radio
Rev. 01 — 4 February 2008
Access Value
R/W
Access Value Description
R/W
0
1*
000 0001
000 0010
000 0100
000 1000
001 0000*
010 0000
100 0000
0*
1
51h
5Ch
67h*
72h
7Dh
08h
13h
1Eh
29h
34h
3Fh
XXh
the IF AGC output voltage can be forced externally
to a fixed voltage, determined by IF_AGC_EXT
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.
IF AGC normal operation
IF AGC output voltage determined by
D_FORCE_VAL
0 dB
+6 dB
+12 dB
+18 dB
+24 dB
+30 dB
+36 dB
+42 dB
+48 dB
don’t care if D_FORCE = 0
12 dB
6 dB
Description
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.
digital IF AGC 3 dB-loop bandwidth setting
limitation off
limitation on
25 Hz
50 Hz
100 Hz
200 Hz
400 Hz
800 Hz
1.6 kHz
TDA8295
© NXP B.V. 2008. All rights reserved.
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