BenQ PB8250 - XGA DLP Projector, Service Manual

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DEN – Data enable signal output to DMD BD , provided as a valid data indicator signal for
DMD driver.
VCLK – V-port pixel clock.
VPEN – V-port data enable.
VVS – V-port Vertical Synchronization.
VHS – V-port Horizontal Synchronization.
VFILED – V-port Even/Odd frame indicator.
RESETZ – Output to DMD driver BD as RESETZ signal for DMD normal operation.
ABNORMAL – Input to CPU for indicating abnormal condition , if the CPU detects an
abnormal status , it will disable lamp ignition.
POWERON – Output to power to enable the other power source into normal working situation.
LAMPLIT – Input signal as an indicator that the Lamp is ON or OFF
LED1, LED2 – Output to enable the LED ON or OFF.
IRRCVR0 – System IR input to CPU as remote control signals.
MCKEXT – Memory clock to CPU.
DCKEXT – Data clock to for Scaling.
I2C_SDA , I2C_SCL – I2C format data transfer line.
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EEPROM
Store the system information for user friendly .
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Flash Memory
System software was stored in this chip , the memory size is 8M bits
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DDP1000
The DDP1000 transfer signal from PW166 to DMD for driving DMD mirror operation.
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Direct Rambus Memory
The DDP1000 utilizes a high speed Direct Rambus Memory. To support the RDRAM a Direct
Rambus clock generator CDCR83 is utilized. It can transfer input clock from 50MHz to
400MHz.
IR Receiver schematic:
The IS1U621 is miniaturized receivers for infrared remote control systems. PIN diode and
pre-amplifier are assembled on lead frame, the epoxy package is designed as IR filter. The
demodulated output signal can directly be decoded by a microprocessor. The main benefit is the
reliable function even in disturbed ambient and the protection against uncontrolled output pulses.
Electronic System Protection for abnormal state:
The circuit of electronic system protection for abnormal state is used for the hardware light off and
power off in abnormal state of thermal and safety issues. If the protection function is active then the
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