ADVANCED INFORMATION
NOV, 1997
LMC7532
Low EMI, Low Power XGA/SVGA TFT-LCD Column Driver
General description
Feature
The LMC7532 is a Column Driver suitable for Nation-
al’s 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.
■ Reduced Swing Differential Signalling (RSDS)™
digital bus reduces power, EMI and width from tim-
ing controller.
■ Selectable 300/309 outputs provides ability to
drive SVGA and XGA TFT-LCD systems.
■ Switched reference type DAC gives high accuracy
with low reference current requirements.
■ Clock Frequency up to:
■ Typical Accuracy:
■ Narrow bus.
65MHZ
+/-5 mV
■ 64 gray scales.
■ Receive RSDS @ 130Mb/s width @ 65MHz clock
from FPD 63310.
With the addition of a single National DS90CF364 or
‘564 FPD-Link™ chip, and the FPD63310 Universal
Interface XGA/SVGA Timing controller, the entire data
path is optimized for reduced EMI, power consump-
tion and width.
System Diagram
Gray Scale Voltage Reference BUS
Gray scale
Reference
Line Transfer Signal
/9 + CLK, RSDS BUS
Start Pulse
Start Pulse
LMC7532
LMC7532
LMC7532
LMC7532
Inversion
Control
A1
An
/2 Link1
/2 Link2
/2 Link3
FPD63310
XGA Panel
Timing
Controller
/2 LinkC
1024 X 768 or 800 X 600
TFT-LCD Array
VDD
VSS
Panel
Power
Supply
NM93CSxxL
Serial EEPROM
E1
En
FIGURE 1. Block diagram of the LCD module
FPD-Link™ is a trademark of National Semiconductor
©1997 NSC
1
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