In 3.3V power system, the VDD and VDD3 are connected to 3.3V power, all output pins swing from 0~3.3V,
HSYNC, VSYNC and open drain pin can accept 0~5V input range, other pins must be kept below 3.3V. And the
ADC conversion range is 3.3V.
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 12V 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 AC output.
The output stage consists of a
tuning capacitor, transformer, and push-pull MOSFET
pair to boost AC output up
to hundreds of voltage peak to peak.
And one resister is serial to lamp for output voltage feedback.
There are two signals which control the inverter come from system to turn on the inverter and control brightness.
Logic “low” level which send to I901 is turn on the inverter.
BRI signal control brightness by DC level which was integral from PWM signal.
POWER CONFIGURATION
The MTV312M can work on 5V or 3.3V power supply system.
In 5V power system, the VDD pin is connected to 5V power and the VDD3 needs an external capacitor, all
output pins can swing from 0~5V, input pins can accept 0~5V input range.
And ADC conversion range is 5V. However, X1 and X2 pins must be kept below 3.3V.
C. MTV312M64
The MTV312M micro-controller is an 8051 CPU core embedded device especially tailored for CRT/LCD
Monitor applications. It includes an 8051 CPU core, 1024-byte SRAM, 14 built-in PWM DACs, VESA DDC
interface, 4-channel A/D converter, and a 64K-byte internal program Flash-ROM.
A “CMOS output pin” means it can sink and drive at least 4mA current. It is not recommended to use such
pin as input function.
A “open drain pin” means it can sink at least 4mA current but only drive 10~20uA to VDD. It can be used as
input or output function and needs an external pull up resistor.
A “8051 standard pin” is a pseudo open drain pin. It can sink at least 4mA current when output is at low level,
and drives at least 4mA current for 160nS when output transits from low to high, then keeps driving at 100uA to
maintain the pin at high level. It can be used as input or output function. It needs an external pull up resistor when
driving heavy load device.
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Summary of Contents for ve510b/s-21
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