ViewSonic VG720 - 17" LCD Monitor Service Manual page 18

4.4 INTRODUCTION OF IC
STUM56AK(U401): integrate ADC, OSD, SCALER, MCU, LVDS, convert analog RGB
PIN Function:
Pin
70
71
72
73
65 DDCA_SDA/RS232_TX DDC data for analog interface; 4mA driving
66 DDCA_SDA/RS232_RX DDC
36
37
19
22
11
63
64
62
61
51
21
29
4
33
34
44 50
60
52
34
14 67 95
103 115
13 38 41
47 96 116
AIC1084-33PM (U702): DC power convert, used to 5v convert 3.3v.
LT1117-18(U701): DC power convert, used to 5v convert 3.3v.
ViewSonic Corporation
into digital and room and shrink scaling output to LCD panel.
Symbol
SDO
CSZ
SCK
SDI
DDCD_SDA
DDCD_SCL
RST
RSTN
VCTRL
HSYNCO
VSYNCO
REFP
REFM
REXT
PWM1
PWM0
BYPASS
XIN
XOUT
AVDD DVI
AVDD ADC
AVDD PLL
AVDD MPLL
VDDP
VDDC
SPI flash serial data output; Input w/5V-tolerant
SPI flash chip select; output
SPI flash serial select; output
SPI flash serial data input; output
strength/UART transmitter/GPIO; I/O w/5V-tolrant
data for
transmitter/GPIO;Input w/5V-tolrant
DDC data for DVI interface; 4mA driving strength;
I/O w/5V-tolerant
DDC clock for DVI interface; Input w/5V-tolerant
Chip reset; High reset; Input w/5V-tolerant
Chip reset; Low reset; Input w/5W-toerant
Regulator control; Output
Analog HSYNC input
Analog VSYNC input
Internal ADC top de-coupling pin
Internal ADC bottom de-coupling pin
External resistor 390 ohm to AVDD DVI
PWM1; 4mA driving strength; Output
PWM0; 4mA driving strength; Output
For External Bypass Capacitor
Xin; Crystal Oscillator Input
Xout; Crystal Oscillator Output
DVI Power 3.3V
ADC Power 3.3V
PLL Power 3.3V
MPLL Power 3.3V
Digital Output Power 3.3V
Digital Core Power
- 18 –
Description
analog interface/UART
1.8V
Confidential - Do Not Copy VG720