Sharp LC-22LE240E, Service Manual

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LC-22LE240
CIRCUIT DESCRIPTIONS
1
. TUNER(TU3)
A horizontal mounted and Digital Half-Nim tuner is used in the product, which covers 3
Bands(From 48MHz to 862MHz for COFDM, from 45.25MHz to 863.25MHz for CCIR CH).
The tuning is available through the digitally controlled I2C bus (PLL). Below you will find
info about the tuner.
In active antenna option, the following circuit are used. ANT_CTRL pin is controlled by
microcontroller. If ANT_CTRL is low, ANT_PWR will be low. If ANT_CTRL is high,
ANT_PWR will be high.
OVER_CUR_DETECT pin is a monitor for short circuit in antenna. OVER_CUR_DETECT
is low, ANT_CTRL will be low, so ANT_PWR will be low. Finally, short circuit protection is
done by circuits and microcontroller.
1.1. General description of Sony RE216:
The SUT-RE216 is designed for terrestrial TV (digital & analog) and digital cable
reception. It includes a full band tuner and a channel filtering for digital signals. It provides
a low IF output after channel filtering to drive a channel demodulator. Tuning, band
switching and initialization are made via an I2C bus
interface. The module is built on a low-loss printed
circuit board carrying all the components in a metal
housing frame with top and rear covers. The single
aerial connector is mounted on one frame side and all
other connections are made via pins at the bottom.
Features:

Full frequency range from 47 to 870 Mhz

Digital Platform (DVB-T/T2, DVB-C, ISDB-T & ATSC)

Analog platforms (PAL B/G/I/D/K, NTSC M & SECAM L/L’)

Low IF tuner concept