
7-2
1 Power Circuit
1.1 Power input
12V DC input from power Board through J601 to interface.
1.2 Soft-power circuit
IC602 control the Q602 and Q601 for 12V into the DC to DC circuit .
IC602 pin5 Low is OFF status ; Hi is ON status
While “ON” status DC to DC circuit output 5V and 3.3V
While “OFF” status DC to DC circuit is not activity.
1.3 DC to DC circuit
IC610 is used generate the system power. It have built in 2 channel PWM controller to provide two voltage
output.
One (5V) is provide panel Vcc and 2.5V regulator input.
The other (3.3V) is provide the Scaler and MCU power.
1.4 Panel Vcc control
Panel power control used Q301 and IC301 from IC102 (pin19) PANELVCC_CTL.
While the PANELVCC_CTL stay at High level ;the panel voltage is 5V.
While the PANELVCC_CTL stay at Low level ;the panel voltage is 0V.
2 Microprocessor Control circuit
2.1 clock circuit
The X101 is crystal ;it generates an 12M Hz output for microprocessor.
2.2 I2C buses
IC102 (pin 40) SDA Serial data
IC102 (pin 39) SCL Serial clock
This is I2C serial communication bus and is used for READ or WRITE data communication of IC101 and
IC401.
2.3 General-purpose port
2.3.1 Key scan status
IC102 pin2 is for OSD “Menu” adjust
IC102 pin3 is for OSD “Select” adjust
IC102 pin4 is for OSD “Up” adjust
IC102 pin5 is for OSD “Down” adjust
2
.3.2 Scaler control
IC102 pin14 (I/O) for scaler interrupt signal
IC102 pin 30 output scaler reset signal