4. Circuit Description
(VE510s-4/VE510b-4)
A. AC-DC
CONVERTER
The power supply with a high-integrated green-mode PWM controller provides several
features to enhance the performance of power flyback converters.
I801 is a PWM controller and provides many protection functions.
I802 is a photo couple to transfer the feedback signal from the second side which I803
detected both of the output DC voltage on 3.3V and 12V.
D813 detected the working voltage on I801 and Q805 would pull down the voltage on I801
pin5 to shut down I801 if feedback loop was failed.
R826 would be a dynamic load which was active while backlight was turned off and system
still working on, this kept 12V output voltage under 13V to protect the panel. After system
went to power saving mode, the R826 would no loaded. This was detected by I804 and Q803
active the R826 to load or not.
B. Scaling
controller
The RTD2013 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 XGA into XGA resolution
that panel can acknowledge.
General
Embedded dual DDC support DDC1, DDC2B,DDC/CI
Zoom scaling up and down
Embedded Pattern Generator
No external memory required.
Require only one crystal to generate all timing
Embedded reset control output
Embedded crystal output to MICROP
3 channels 8 bits PWM output, and selectable PWM clock frequency.
PIN DESCRIPTION
(I/O Legend: A= Analog , I=Input ,O=Output ,P=Power ,G=Ground)
■
ADC: 15 pins
Name I/O
Pin
No
Description
Note
ADC_ GND
AG
27
ADC ground
ADC_REFIO
AP
28
ADC band-gap voltage de-coupling 1.20V
ADC_VDD AP
29
Analog
power
(3.3V)
BLUE+
AI
30
Analog input from BLUE channel
BLUE-
AI
31
Analog input ground from BLUE
channel
ADC_ GND
AG
32
ADC ground
SOG/ADC_TEST AIO
33
SOG
in/ADC test pin
GREEN+
AI
34
Analog input from GREEN channel
GREEN-
AI
35
Analog input ground from GREEN
channel
ADCB_VDD AP
36
Analog
power
(3.3V)
RED+
AI
37
Analog input from RED channel
RED_
AI
38
Analog input ground from RED
channel
ADC_GND AG
39
Analog
ground
ADC_GND AG
40
Analog
ground
15
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Corporation
Co
nfidential
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Do
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VE510s-4_VE510b-4
Содержание VE510b-4
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Страница 71: ...11 3 CON PCB TOP VIEW 69 ViewSonic Corporation Confidential Do Not Copy VE510s 4_VE510b 4...
Страница 72: ...11 4 CON PCB BOTTOM VIEW 69 ViewSonic Corporation Confidential Do Not Copy VE510s 4_VE510b 4...
Страница 74: ...11 6 POWER PCB BOTTOM VIEW 71 ViewSonic Corporation Confidential Do Not Copy VE510s 4_VE510b 4...