ViewSonic VA903b-3 VS11372, Руководство по обслуживанию

Страница: 24 / 84

ViewSonic Corporation
Confidential - Do Not Copy
VA903b-1_ VA903m-1
21
3.3V Ground G 48,120 GNDIO: 2
3.3V Power P 58,71,83,95,110 PVCC: 5
3.3V Ground G 57,72,84,96,109 PGND: 5
2.5V Power P 45,69,98,127 VCCK: 4
2.5V Ground G 44,70,97,128 GNDIK: 4
Note: (1) TTL compatible CMOS Input (Vt=1.7V); VCC=3.3V;
(2) 5V tolerance pad;
(3) Internal 75K Ohms pull high resistor.
(4) Internal 75K Ohms pull low resistor.
(5) Schmitt trigger CMOS Input (Vt=1.4-~2.2V);
(6) Open-Drain, Output Drive low & Pull-high.
(7) Bi-directional input/output
(8) Programmable driving current (2~10mA)
(9) TTL output 5V & 3.3V
(10) 4V tolerance pad
C, MTV512M
The MTV512M micro-controller is an 8051 CPU core
embedded device especially tailored for flat panel
display applications. It includes an 8051 CPU core,
768-byte SRAM, 4 channels of 6-bit ADC, 3 external
counters/timers, 6 channels of PWM DAC, VESA
DDC interface, and a 64K-byte internal program
Flash-ROM memory in 44-pin PLCC package
FEATURES
• 8051 core, 12MHz operating frequency with
single/double CPU clock option
• 0.35um process; 3.3V power supply
• 768-byte RAM; 64K-byte program Flash memory
• Maximum 6 channels of PWM DAC
• Compliant with VESA DDC1/2B/2Bi/2B+ standard
• Dual slave IIC addresses; two H/W auto transfer
DDC1/DDC2x data for both D-sub and DVI
interfaces
• Watchdog timer with programmable interval
• 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