Color Liquid Crystal Display Controller
LH79524/LH79525 User’s Guide
4-2
Version 1.0
4.1.1 LCD Panel Architecture
Modern technology panels, including AD-TFT and HR-TFT panels, are thinner than ever.
To achieve maximum space savings, they are manufactured without the large ASICs and
DC-DC converter blocks built into STN and TFT panels. See Figure 4-2.
The ASIC in STN and TFT panels decodes input data into Row and Column information
and builds the timing signals. It supplies this information to the panel’s Row and Column
driver chips to set the proper pixels at the proper intensity and at the proper times. The
DC-DC converter runs the panel’s power supplies and illuminator. Including these devices
in STN and TFT panels, however, comes at the cost of bulk and weight.
The ALI eliminates the need for a separate Timing ASIC, since it is able to drive the panel’s
Row and Column driver chips directly. The DC-DC conversion is also handled off-panel,
by a separate device operating the panel’s high voltage supplies and illuminator. The
DC-DC conversion must be handled by a separate device, since the LH79524/LH79525
do not supply this function.
Unless the behavior is different, this User’s Guide uses the term TFT to discuss all types
of TFT panels whether the panel requires timing support from the ALI or not.
Figure 4-2. Block Diagram of a Typical Advanced LCD Panel
DC/DC
CONVERTER
TIMING
ASIC
ROW TIMING
LCD PANEL ASSEMBLY
COLUMN TIMING
LCD
PANEL
GLASS
DISPLAY
SIGNALS
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