Hyundai ImageQuest P990+ Technical & Service Manual page 13

P990+ Technical Service Manual
1) The small signal video amplifier controlled by MCU via I
contrast(main gain control), 3 sub cut-off controls(R Cut-off, G Cut-off, B Cut-off), clamping pulse
source and the clamping pulse width.
2) The OSD mixer processes the OSD-R,OSD-G,OSD-B on Pin13,14,15 and the OSD Blk input on
Pin1 and the OSD contrast is controlled by MCU via I
3) The H-Blanking signal is sent to the pin19 of 01.
To turn off the Horizontal scan Line during horizontal retrace period.
The Video-Power-Amplifier ICC03 is a 3-channel hybrid-IC which functions as a cascade type transistor
amplifier to reach the high bandwidth performance.
The Cutoff-Adjusting circuit consist of QC03, QC05, QC07, QC04, QC06 and QC08 is to provide the
function of dark/background white-balance control by varying the peak voltages on the CRT cathodes.
ICC03(LM2402) serving as the OSD generator outputs the R,G,B,FBKG(FBLK) signals that contain the
information by which the MCU shows the monitor's status and the user adjusting indications. The
R,G,B,FBKG signals are synchronized by the horizontal and vertical deflection sync input on Pin5 and
Pin10. The MCU controls the OSD via the signals,SDA,SCL on Pin 7,8.
Horizontal Deflection B+ Control Circuit
H/V Processing circuit
H/V Processing IC TDA4841 is I2C-autosync deflection controller for PC monitor.
All functions are controllable by I2C-bus.
The TDA4841 provides syncronization processing, horizontal and vertical synchronization with full
autosync capability.
HSYNC(Pin15) is the input horizontal syncronization signals, which can be DC-coupled TTL signals
and AC-coupled negative-going video sync signals.
The IC generates the drive waveforms for DC-coupled vertical boosters such as TDA4841 and
KA2142
The TDA4856 provides extended functions e.g. as a flexible B+ control, an extensive set of geometry
control facilities, and an combined output for horizontal and vertical focus signals.
External power components are given a great deal of protection.
The X-ray protection input X-Ray (Pin2) provides a voltage detector with a precise threshold.
In normal state, the pin2 voltage is about 5.3V. If incresing the high voltage, pin2 voltage is increased.
When pin2 voltage exceeds about 6.3V, TDA4856 is forced into protection mode.
In this mode several pins are forced into defined states:
HUNLOCK is flouting
Horizontal output stage (HDRV) is flouting
B+ control driver stage (BDRV) is flouting
CLBL provides a continuous blanking signal
The supply voltage of the IC must be switched off for a certain time, before the IC can be restarted again
using the standard power-on procedure.
* Refer to the Schemathics in the Page 61 (Schematic Diagram 4-2)
C bus for the features of
2
C bus.
2
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