Circuit Description - ViewSonic VA1703w-1 Service Manual

4. Circuit Description

4-1. Power supply (DC/DC Converter)
This brick convert is the 110-220AC input voltage to 12V AND 5V output for inverter,
audio, panel and system controller use.
It consists of a PWM IC (TEA1530AT, U105)
4-2. Scaling controller
The ADC is to convert RGB analog signal to digital signal that scaling chip can
acknowledge.
The HSYNC input receives a logic signal and provides the frequency reference for
pixel clock generation.
The scaling IC is to converts the input signal ranging from VGA to WXGA.
4-3. General description
The TSUM57AK is a high performance, and fully integrated graphics processing IC
solution for LCD monitors with resolutions up to WXGA. It is configured with an integrated
triple-ADC/PLL, a high quality scaling engine, an on-screen display controller, a built-in
output clock generator, and LVDS display interface. To further reduce system costs, the
TSUM57AK also integrates intelligent power management .
ViewSonic Corporation
18
Confidential - Do Not Copy
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