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ViewSonic Corporation
Confidential - Do Not Copy
VG921m-4
30
• Support external counters/timers, 1 & 2
• Single/double frequency clock output
• Two external interrupts, INT1 is shared with Slave
IIC interrupt source.
• Maximum 4 channels of 6-bit ADC
• Flash-ROM code protection selection
• 44-pin PLCC package
D. INVERTER
In order to drive the CCFLs embedded in the panel module, there is a push-pull inverter to convert by the controller.
from input 24V up to hundreds of AC voltage output peak to peak.
The inverter is formed by symmetric in order to drive the separate lamp modules.
The input stage consists of a PWM controller, push-pull inverter, and switching MOSFET to convert DC input into AC
output.
The output stage consists of a tuning capacitor, transformer, and push-pull MOSFET pair to boost AC output up to
hundreds of voltage peak to peak.
And one resister is serial to lamp for output voltage feedback.
There are two signals which control the inverter come from system to turn on the inverter and control brightness.
Logic “low” level which send to U901 is turn on the inverter.
BL-ADJ signal control brightness by DC level which was integral from PWM signal.
Summary of Contents for VG921m-4 VS11369
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Page 48: ...ViewSonic Corporation Confidential Do Not Copy VG921m 4 45 Setp4 3 Check the DDC...
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