1FEATURES
2• Complies with Open LDI Specification for
Digital Display Interfaces
• 25 to 85MHz Clock Support
• Supports VGA through UXGA Panel
Resolution
• Up to 4.76Gbps Bandwidth in Dual 24-bit RGB
In-to-Dual Pixel Out Application
• Dual 12-bit Double Pumped Input DVO Port
• Pre-Emphasis Reduces Cable Loading Effects
• Drives Long, Low Cost Cables
• DC Balance Data Transmission Provided by
Transmitter Reduces ISI Distortion
• Transmitter Rejects Cycle-to-Cycle Jitter (±2ns
of Input Bit Period)
• Support both LVTTL and Low Voltage Level
Input (Capable of 1.0 to 1.8V)
• Two-Wire Serial Communication Interface up
to 400 KHz pin•
Programmable Input Clock and Control Strobe
Select
• Backward Compatible Configuration with
112MHz LDI and FPD-Link inter•
Optional Second LVDS Clock for Backward
Compatibility with FPD-Link Receivers
• Compatible with TIA/EIA-644

DESCRIPTION
The DS90C387R transmitter is designed to support
pixel data transmission from a Host to a Flat Panel
Display up to UXGA resolution. It is designed to be
compatible with Graphics Memory Controller Hub
(GMCH) by implementing two data per clock and can
be controlled by a two-wire serial communication
interface. Two input modes are supported: one port of
12-bit( two data per clock) input for 24-bit RGB, and two ports of 12-bit( two data per clock) input for dual
24-bit RGB( 48-bit total). In both modes, input data
will be clocked on both rising and falling edges in
LVTTL level operation, or clocked on the cross over of differential clock signals in the low swing operation.
Each input data width will be 1/2 of clock cycle. With
an input clock at 85MHz and input data at 170Mbps,
the maximum transmission rate of each LVDS line is
595Mbps, for a aggregate throughput rate of
2.38Gbps/4.76Gbps. It converts 24/48 bits
(Single/Dual Pixel 24-bit color) of data into 4/8 LVDS (Low Voltage Differential Signaling) data streams.
DS90C387R can be programmed via the two-wire
serial communication interface. The LVDS output pin•
out is identical to DS90C387. Thus, this transmitter
can be paired up with DS90CF388, receiver of the 112MHz LDI chipset or FPD-Link Receivers in non-
DC Balance mode operation which provides GUI/LCD
panel/mother board vendors a wide choice of inter•
operation with LVDS based TFT panels.
DS90C387R also comes with features that can be
found on DS90C387. Cable drive is enhanced with a
user selectable pre-emphasis feature that provides
additional output current during transitions to
counteract cable loading effects. DC Balancing on a
cycle-to-cycle basis is also provided to reduce ISI
(Inter-Symbol Interference), control signals (VSYNC,
HSYNC, DE) are sent during blanking intervals. With
pre-emphasis and DC Balancing, a low distortion eyepattern
is provided at the receiver end of the cable.
These enhancements allow cables 5 to 15+ meters in
length to be driven depending on media characteristic
and pixel clock speed. Pre-emphasis is available in
both the DC Balanced and Non-DC Balanced modes.
In the Non-DC Balanced mode backward
compatibility with FPD-Link Receivers is obtained.