tda18219hn NXP Semiconductors, tda18219hn Datasheet - Page 14

• Manufacturer Part Number: tda18219hn
• Description: Silicon Tuner For Terrestrial And Cable Digital Tv Reception
• Manufacturer: NXP Semiconductors

NXP Semiconductors
Table 13.
TDA18219HN_1
Objective data sheet
Address Register
0Ch
0Fh
10h
11h
12h
AGC1_byte_1 7
RF_AGC_byte
_1
IR_MIXER_
byte_1
AGC5_byte_1 3 to 0
IF_AGC_byte
AGC and Take Over Points bit descriptions
10.1.6 AGC and Take Over Points (TOP)
Bit
6
3 to 0
7
6 to 5
3
2 to 0
3 to 0
2 to 0
Symbol
LT_Enable
AGC1_6_15dB
AGC1_TOP[3:0]
PD_RFAGC_Adapt
RFAGC_Adapt_TOP[1:0] R/W
RF_Atten_3dB
AGC3_TOP[2:0]
AGC4_TOP[3:0]
AGC5_TOP[3:0]
IF_Level[2:0]
Rev. 01 — 3 February 2010
Silicon Tuner for terrestrial and cable digital TV reception
Access Value
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
1
0
1
see
Table 14
0
1
-
0
1
see
Table 15
see
Table 16
see
Table 17
see
Table 18
Description
LT output
limits AGC1 gain range from +6 dB to
+15 dB
set the TOP of the LNA detection loop
(AGC1) in accordance with the
reception standard or the system
settings.
RF AGC adapts algorithm power-down
“AGC3 Adapt” algorithm decreases the
AGC3 TOP for low LPF gains. LPF
gain is put to low value by AGC5
detector loop in the ACI (N) and
(N − 1) reception cases. Decreasing
the AGC3 TOP then limits signal C / N
(Carrier / Noise) degradation caused
by distortion in the RF stages. At
opposite, LPF gain is put to high value
by AGC5 detector loop in the ACI
(N − X) and (N + X) reception cases.
Increasing the AGC3 TOP then limits
signal C / N degradation caused by
noise from RF AGC stage.
PD_RFAGC_Adapt allows disabling
this algorithm. RFAGC_Adapt_TOP
allows choosing the low AGC3 TOP
value, the high one being chosen via
the AGC3 TOP field.
Adds 3 dB attenuation out of RF AGC
sets the RF AGC, MIXER and LPF
blocks TOP. These bits must be set
according to the desired reception
standard and required desired
performances
sets the tuner desired maximum output
level. This will enable internal
computation of the best linearity/noise
compromise based on desired output
level
disable
enable
range is from −12 dB to +15 dB
range is from +6 dB to +15 dB
ON
OFF
OFF
ON
TDA18219HN
© NXP B.V. 2010. All rights reserved.
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