ADVANCED INFORMATION
NOV, 1997
LMC7532
Low EMI, Low Power XGA/SVGA TFT-LCD Column Driver
General description
The LMC7532 is a Column Driver suitable for Nation-
al鈥檚 Reduced Swing Differential Signalling (RSDS)
digital interface. It converts this 18-bit digital data into
analog voltage for 300 or 309 columns, charging each
sub-pixel to the correct gray level corresponding to the
digital value.
The RSDS path to the panel timing controller contrib-
utes toward lowering radiated EMI, reducing system
power consumption and eliminates one of the two pix-
el busses used in typical XGA TFT-LCD panels today.
This single 9-bit differential bus conveys the 18-bit
color data for XGA panels at 130Mb/s when using
VESA 60 Hz standard timing.
With the addition of a single National DS90CF364 or
鈥?64 FPD-Link鈩?chip, and the FPD63310 Universal
Interface XGA/SVGA Timing controller, the entire data
path is optimized for reduced EMI, power consump-
tion and width.
Feature
s
Reduced Swing Differential Signalling (RSDS)
鈩?/div>
digital bus reduces power, EMI and width from tim-
ing controller.
s
Selectable 300/309 outputs provides ability to
drive SVGA and XGA TFT-LCD systems.
s
Switched reference type DAC gives high accuracy
with low reference current requirements.
65MHZ
s
Clock Frequency up to:
+/-5 mV
s
Typical Accuracy:
s
Narrow bus.
s
64 gray scales.
s
Receive RSDS @ 130Mb/s width @ 65MHz clock
from FPD 63310.
System Diagram
Gray Scale Voltage Reference BUS
Line Transfer Signal
/9 + CLK, RSDS BUS
Start Pulse
Gray scale
Reference
Inversion
Control
/2 Link1
/2 Link2
/2 Link3
/2 LinkC
LMC7532
1
n
LMC7532
1
n
LMC7532
1
n
LMC7532
1
n
Start Pulse
A1
DS90CF564
/364
FPD-Link
FPD63310
XGA Panel
Timing
Controller
R
A
An
Gate Clock
1024 X 768 or 800 X 600
TFT-LCD Array
VDD
VSS
R
E
En
Panel
Power
Supply
NM93CSxxL
Serial EEPROM
E1
FIGURE 1. Block diagram of the LCD module
FPD-Link鈩?is a trademark of National Semiconductor
漏1997 NSC
1
http://www.national.com
1
2
