Advertisement
-Enhanced 80C51 microprocessor core;
-Internal program memory (48 Kbytes ROM and 1 Kbytes RAM);
-High performance OSD;
-Closed Caption decoder;
-I2C bus serial I/O;
-Only one reference (12 MHz) crystal for all internal timing;
-Multi-standard vision IF circuit (45.75 MHz) with PLL demodulator;
-PAL/NTSC color decoder with automatic search system;
-Integrated luminance and chrominance circuit;
-RGB control circuit;
-8V and 3.3V supply voltages;
-Horizontal and vertical geometry processing.
An external E2PROM (IC102) with 4 Kb is used to keep the setup and calibration configuration by I2C bus
(channels, volume, horizontal and vertical geometry, etc.).
Front panel buttons and IR decoders are also realized by IC101.
7.3 - TUNER
TU201, SF201 and surrounding components (2xx).
This is a standard Frequency Synthesizer Tuner (FST Tuner) which covers VHF and UHF channels,
including cable channels (frequency range from 55.25 MHz to 801.25 MHz).
This device is controlled by I2C bus. The output signal (IF output) is connected to the IC101 through a SAW
filter (SF201).
7.4 - AV SWITCHES
Q330, Q331, Q340, Q351, Q341, Q350, IC490 and surrounding components.
The external audio and video signals (AV1, AV2, AV3) are selected by the Micro Controller using two output
signals (SW0_pin10 and SW1_pin11 IC101). The video signals are selected using standard transistors and
the audio signals are selected using the IC490 (4052)
The selected video signal is connected to the TV signal processor external video input and the selected
audio signal is connected to the TV signal processor (mono models) or to the stereo decoder (stereo
models).
7.5 - STEREO DECODER
IC450, Q450, Q450R and surrounding components.
This circuit is used only in stereo models and the main device is TDA9855 (stereo decoder).
Using I2C bus, the IC101 can identify a stereo and SAP signals.
This device combines stereo decoder and audio processor. In stereo models, this device offers automatic
volume level control, special effects, volume control, bass control and treble control.
7.6 - AUDIO OUTPUT
IC401, Q401, SP401, SP401R and surrounding components.
The main device is TDA7499 (stereo amplifier). The output signal is a 3+3 Watts with a 16 ohms speakers.
The input signals come from the stereo decoders or from the TV signal processor (mono models).
This circuit uses external mute system (Q401) to minimize speaker noise during turn on/off.
7.7 - VIDEO OUTPUT
Q810, Q811, Q820, Q821, Q830, Q831 and surrounding components.
The RGB signals from micro controller are amplified to the CRT using a standard transistors configuration.
32
Advertisement
