Main Board Parts - Samsung LS15HAA Service Manual

13 Circuit Descriptions

Main Board Parts

13-1-2
1. Inverter: A conversion device that converts DC
rated voltage/current to high ones necessary
for the panel lamp.
2. DC/DC(Regulator): General term for DC to DC
converting devices.
The IP board receives 5V and outputs 1.8 or
3.3V that is supplied to the scaler (SE56AWL).
3. Power MosFET: The IP board receives 5V and
outputs a lower voltage in DPMS mode and
supplies the whole 5V for the panel operating
board in normal conditions. In that case, the
switching of Power MosFET is controlled by
Micom.
4. Scaler: Receives the digital TMDS and analog
R,G,B signals and convert them to proper reso-
lutions using up- or down- scaling that are
transferred to the panel in the LDVS formats.
5. Crystal(Oscillator): Use one 24MHz oscillator
externally to supply power to both MCU and
Scaler at the same time.
13-2
6. MCU & EEPROM: I2C is a two-way serial bus of
two lines that supports communications across
the integrated circuits as well as between MCU,
Scaler and EEPROM.
In particular, MCU and Scaler (SE56AWL) use
the DDR direct bus for mutual communications,
which is an effective, speedy system because it
allows 4 additional address/data lines com-
pared to the old serial systems.
7. Function Key: A certain keystroke generates a
certain electrical potential, which is transferred
into ADC input port of the MCU and then con-
verted to a digital value by the A/D converter of
the chip. The digital value (data) is a clue to
which key is entered. In practical, the voltage
levels are set as below.