Sharp LC-24LE250EK (serv.man2) Service Manual ▷ View online
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LC-24LE250 (C)
1.1 General Block Diagram
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15.
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LC-24LE250 (C)
1.2 Placement of Blocks
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LC-24LE250 (C)
CIRCUIT DESCRIPTIONS
4
2.
TUNER
A.
SI2156 Terrestrial and Cable TV Tuner:
A.1. Description:
The Si2156 integrates a complete hybrid TV tuner supporting all worldwide terrestrial and
cable TV standards. Leveraging Silicon Labs’ field proven digital low-IF architecture, the
Si2156 maintains the unmatched performance and design simplicity of the Si2153 while
further reducing footprint size and bill of materials cost. No external LNAs, tracking filters,
wirewound inductors, or SAW filters are used.
Compared with competing silicon tuners and discrete MOPLL-based tuners, the Si2156
delivers superior picture quality and a higher number of received stations in crowded and
near/far real-world reception conditions. The high linearity and low noise RF front-end
delivers superior blocking performance and higher sensitivity in the presence of strong
undesired channels and interference.
The Si2156 integrates the complete signal path from antenna input to IF outputs for both
analog and digital transmission standards. Compared to traditional discrete MOPLL-based
tuners, the Si2156 eliminates hundreds of external components including external LNAs,
tracking filter varactors and inductors (unlike competing silicon tuners), and SAW filters,
resulting in the simplest, lowest-cost BOM for a hybrid TV tuner.
Interfacing the Si2156 seamlessly with the Si2165 DVB-T/C demodulator creates a
complete terrestrial and cable DVB-T/C receiver plus PAL/SECAM tuner.
A.2. Features:
- Worldwide hybrid TV tuner
- Analog TV: NTSC, PAL/SECAM
- Digital TV: ATSC/QAM, DVB-T/C, ISDB-T/C, DTMB
- 42-1002 MHz frequency range
- Compliance to A/74, NorDig, D-Book, C-Book, ARIB, EN55020, OpenCable™
specifications
- Best-in-class real-world reception
- Exceeds discrete MOPLL-based tuners
- Highly integrated, lowest BOM
- No SAW filters or wirewound inductors required
- Integrated LNAs and complete tracking filters
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LC-24LE250 (C)
5
- No alignment, tuning or calibration required
- Digital low-IF architecture
- Integrated channel select filters
- Flexible output interface
- ALIF to analog TV demodulator or SoC
- DLIF to digital TV demodulator or SoC
- 3.3 and 1.8 V power supplies
- Standard CMOS process technology
- 5 x 5 mm, 32-pin QFN package
- RoHS compliant
Figure 1: Pin description
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