Samsung 940BW Service Manual page 20

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
(SE657MRH-LF).
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 14.318MHz
oscillator externally to supply power to both
MCU and Scaler at the same time.
13-2
6. Scaler & EEPROM: I2C is a two-way serial bus
of two lines that supports communications
across the integrated circuits as well as
between FLASH and EEPROM.
In particular, MCU(SE657MRH-LF) and use the
SDR 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.