User’s Guide of SSD1963 Eval Rev2A
Doc. version 1.0b 8
th
Feb 2010
Page
3
1.
Voltage regulators for 5V, 3.3V, and 1.2V driving LED backlight (5V), interface
supply power for LCD and digital I/O (3.3V), as well as the core supply
voltage (1.2V) for SSD1963.
2.
Four FPC connectors (J1~J4) for different LCD panels. There are dozens of
TFT pin-out definitions as there is no industrial standard for this. Only four
connectors will not cover all of the TFT interfaces but at least four panel sizes
have been verified including 3.5”, 4.3”, 5.6”, and 7” TFT panels on this
evaluation board.
3.
Two FPC connectors (J5, J6) of bottom contact for touch panels. Some panels
have individual FPC for Touch Panel while others have Touch Panel signal
integrated with data bus on a single FPC. These FPC connectors of 0.5mm and
1.00mm pitch provide a convenient access to Touch Panel signals in case the
signals are separated from the data-bus-FPC. This is very common for large
panel size like 5.6” and 7” panels.
4.
Two LED backlight circuits for
a.
High voltage 20mA constant current white LED driver (CAT4237, On
Semiconductor Inc). The CAT4237 is a DC/DC step-up converter that
delivers an accurate constant current source driving 6 to 8 white LEDs
in series. Output of CAT4237 is routed to J3 and J4 for 4.3” and 3.5”
panels, respectively.
b.
22V high current boost white LED driver (CAT4139, On
Semiconductor Inc). The CAT4139 is a DC/DC step-up converter that
delivers an accurate constant current ideal for driving parallel strings
of up to five white LEDs in series or up to 22V. TFT panels of larger
size (>5.6”) require a lot more white LEDs than small panels. Let’s take
an example from our 7” TFT panel. The white LEDs are organized in 8
parallel groups of 3 LEDs in series as shown in Figure 1.2. The current
required is 160mA (20mA x8) and the voltage requirement is 9.9V.
The CAT4139 is capable of delivering 750mA with voltage as high as
22V under a single 5V DC supply. Output of CAT4139 is routed to the
high voltage connector J7.
Figure 1.2
Backlight configuration of 7” TFT panel
5.
Standard 40-pin 2.54mm box header for MCU interfaces. This box header
provides a direct stack with our PIC24/32 Eval RevC2 board via a flat cable
which is included with every board SSD1963 Eval Rev2A sold.