Dual-Link DVI Second TMDS Data Link Pins

A dual-link DVI interface increases display resolution and refresh rates by adding a second Transition-Minimized Differential Signaling (TMDS) data link to the standard single-link layout. This article outlines the specific pin assignments dedicated to hosting this second TMDS link, detailing the positive and negative differential signal pairs as well as their corresponding ground shields.

On a standard 24-pin DVI connector (found in DVI-D and DVI-I configurations), the primary TMDS link occupies the outer columns, while the second TMDS link occupies the center columns (pins 4, 5, 12, 13, 20, and 21).

The specific pins carrying the second TMDS data channels are:

  • TMDS Data 3 (Link 2, Channel 1):
    • Pin 12: TMDS Data 3− (Negative differential signal)
    • Pin 13: TMDS Data 3+ (Positive differential signal)
  • TMDS Data 4 (Link 2, Channel 2):
    • Pin 4: TMDS Data 4− (Negative differential signal)
    • Pin 5: TMDS Data 4+ (Positive differential signal)
  • TMDS Data 5 (Link 2, Channel 0):
    • Pin 20: TMDS Data 5− (Negative differential signal)
    • Pin 21: TMDS Data 5+ (Positive differential signal)

Associated Shield Pins

To minimize crosstalk and electromagnetic interference, the second link shares dedicated ground shield pins with the first link:

  • Pin 3: TMDS Data 2/4 Shield
  • Pin 11: TMDS Data 1/3 Shield
  • Pin 19: TMDS Data 0/5 Shield

Clock Signal Sharing

The second TMDS link does not possess a separate clock channel. Instead, both the primary link (Data 0, 1, and 2) and the secondary link (Data 3, 4, and 5) share the standard TMDS clock pair located on Pin 23 (TMDS Clock+) and Pin 24 (TMDS Clock−), shielded by Pin 22 (TMDS Clock Shield).