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13 Circuit Descriptions
13-1
13 Circuit Descriptions
13-1 Overall Block Structure
13-1-1 Power Tree
1. When the AD board is in DPMS state:
1.1 The IP has been designed so that it operates with a power consumption of less than 0.6W of.
1.2 The Scaler consumes power up to 37mA
1.3 The power to the panel is switched off
2. When the AD board is operating normally:
2.1 The maximum power consumption of the panel lamps is described below (It may vary depending on
the panel manufacturer)
17" : 4*(7.5mA*650mVrms)=4*4.9=19.6W
19: : 4*(7.5mA*720mVrms)=4*5.4=21.6W
2.2 The power consumption of the Panel Control board is as follows: 5V*720mA=3.6W
2.3 The power consumption of the Scaler is as follows: 3.3V*245mA + 1.8V*300mA = 1.35W
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13 Circuit Descriptions
13-3
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 (GM5726).
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 resolutions 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.
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, FLASH and Scaler (GM5726) use
the SDR direct bus for mutual communications,
which is an effective, speedy system because it
allows 4 additional address/data lines compared 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 Scaler and then converted 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.