Digital LCD Interfaces

CMOS and TTL display interfaces are still in use today, but we are seeing more and more Low Voltage Differential Signaling (LVDS) or LVDS variants being used — especially for larger displays. This provides the advantage of being able to send signals over a relatively long distance though a cable. The disadvantage is that the cable is more difficult to fabricate and a transmitter-receiver chip is required on both ends.

The biggest issue today is with standards. The DVI interface is becoming more commonly used as an emerging standard. With respect to smaller displays, often the graphics interface chip or the controller chip must be provided separately to the display. The manner in which it is connected to the display must be well-understood by the designers.

Another set of interfaces exist for video applications where video interfaces such as NTSC, PAL and RGB are built into the display. They are quite different from conventional graphics interfaces.

DVI interface

The DVI interface was authored by the Digital Display Working Group (DDWG), formed in September of 1998 to provide an open IP, royalty free-environment for digital display standardization.  the DDWG is lead by Intel, Silicon Image, Compaq, Fujitsu, HP, IBM and NEC.

Not currently governed by VESA - version 1.0 released 4/99. It references many VESA standards DDC, EDID, Plug & Display, DFP, DMT and others. DVI does not support USB and IEEE1394, but it will support dual TMDS links for QXGA (2048´1536) at 75Hz refresh.

It requires support for EDID 1.2 and 2.0 and DDC2B

The standard provides digital-only and digital/analog connector formats similar to the Plug & Display connector from Molex, but has fewer contacts.