Level 3 - Component Repair To Curcuit Boards; Theory Of Circuit Operation - BenQ VP2212 Service Manual

Level 3 - Component Repair to Curcuit Boards

Theory of Circuit Operation

Video:
The MST97885ALD is a high performance and fully integrated IC for multi-function LCD monitor/TV with resolutions
up to UXGA(1600x1200) / WSXGA+(1680x1050). It is configured with an integrated triple-ADC/PLL, an integrated
DVI/HDCP/HDMI receiver Note, a multi-standard TV video and audio decoder, a video de-interlacer, a scaling engine,
the MStarACE-3 color engine, an on-screen display controller, an 8-bit MCU and a built-in output panel interface. With
external frame buffer, 2-D video decoding and processing are fulfilled for high-quality TV applications. It supports
de-interlaced full-screen video, frame rate conversion, and aspect ratio conversion for various video sources. To further
reduce system costs, the MST97885ALD also integrates intelligent power management control capability for
green-mode requirements and spread-spectrum supports for EMI management.
Audio:
The TPA3113D2 is a 6-W (Per channel) efficient, Class-D audio power amplifier for driving bridged-tied stereo
speakers. Advanced EMI Suppresion Technology enables the use of inexpensive ferrite bead filters at the outputs
while meeting EMC requirements. SpeakerGuard speaker protection system includes an adjustable and a DC
detection circuit. The adjustable power limiter allows the user to set a "virtual" voltage rail lower that the chip
supply to limit the amount of current through the speaker. The DC detect circuit measures the frequency and
amplitude of the PWM signal and shuts off the output stage if the output stage if the input capacitors are damaged
or shorts exist on the inputs. The TPA3113D2 can drive stereo speakers as low as 4ohm. The high efficiency of the
TPA3113D2, 87%, eliminates the need for an external heat sink when playing music. The outputs are also fully
protected against shorts to GND, VCC , and Output-to-output. The short-circuit protection and thermal protection
includes an auto-recovery feature.
TUNER FEATURES:
INTERMEDIATE FREQUENCIES
System
Picture Carrier
Color Carrier
Sound Carrier
CHANNEL COVERAGE
BAND
Low band
Mid band
High band
FREQUENCY (MHz)
PAL B/G PAL I
38.90 38.90
34.47 34.47
33.40 32.90
FREQUENCY(MHz)
48.25 to 160.00 MHz
160.00 to 442.00 MHz
442.00 to 863.25 MHz
SECAM B/G SECAM D/K
38.90 38.9
34.47 34.47
33.40 32.4
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