Block Diagram; Circuit Description - Sony FWD-42PX2 Service Manual

5-1. Circuit Description

1. Input signal selection circuit
RGB and component signals are input to AD
converters IC88 and IC89 for selection. Video and
audio signals are switched using IC41.
2. A/D converter
This A/D converter consists of IC88 and IC89, and
their peripheral circuits. IC88 and IC89 have
preamplifier and PLL functions as well as an A/D
converter function. The RGB and component signals
from a D-Sub connector are input to the RGB signal
pins of IC88 and IC89. After the input signals are
amplified, they are converted into an 8-bit digital
signal and output to IC14. IC88 also generates a clock
of IC14.
3. Microcomputer and DDC
This microcomputer and DDC consist of IC91, OTP
memory (IC33), I/O controllers (IC2, IC8, IC36, and
IC65), and EEPROM (IC1, IC34, and IC49). IC91
controls the peripheral device using an IIC line. The
major functions are as follows:
1) Memorizes the setting value of a user in IC1.
2) Memorizes EDID data in IC34 and IC49.
4. Video decoder and three-dimensional comb
filter circuit
This video decoder and three-dimensional comb filter
circuit consist of IC59 and IC91 that controls the IIC
line of IC59. CVBS, Y/C, and Y/Pb/Pr signals are
converted into an 8-bit interlace signal using IC59 and
output to the deinterlace block. IC59 adjusts the
contrast, brightness, sharpness, hue, and color density.
The CVBS signal is separated into Y and C signals.
For an NTSC signal, a three-dimensional comb filter is
used.
5. DVT circuit
This DVT circuit consists of IC88 and IC89, and their
peripheral circuits. It processes a component signal of
up to DTV (729P and 1080i). This circuit is controlled
in an IIC line using IC91. It converts the component
signal from a D-Sub connector (CN10) and options 1
and 2 into a digital signal and outputs it to IC14.
FWD-42PX2
Section 5

Block Diagram

6. Audio decoder (digital audio processor)
circuit
This audio decoder circuit consists of IC5 and its
peripheral circuit. IC91 controls this circuit using an
IIC line. An audio signal is digital-processed using
this circuit and output to audio amplifier IC7.
7. Deinterlace block
This deinterlace block consists of IC10 and its
peripheral circuit. IC91 controls this deinterlace block
using an IIC line. IC10 deinterlace- converts an 8-bit
digital interlace YUV signal. The converted signal is
output as a 16-bit digital YUV signal.
8. Panel link circuit
LVDS transmitter IC44 outputs the signal from IC14
to the panel using LVDS. The output signal is
converted into the former signal using the LVDS
receiver on the panel. (Same as for the output of IC14.)
9. Closed caption
The closed caption signal from IC9 is input to IC59
and mixed with a video signal.
5-1