TMDS Video Bus

Transition Minimized Differential Signaling

The Transition Minimized Differential Signaling [TMDS] lines are used on a number of interfaces, P&D, HDMI, and DVI to name a few.
The TMDS signal carries R,G,B and clock through four differential pairs, which occupy 8 pins of a 19-pin connector [shown below].
The operational voltage is 3.3 volts with a trace termination impedance of 50 ohms, DC linked, CML based signals.

TMDS IC Manufacturers

intersil {TMDS Regenerators with Multiplexers, ISL54102}

Maxim {HDMI/DVI Low-Frequency Switching, MAX4929}

nxp {PCIe / DisplayPort-to-DVI / HDMI level shifters, PTN330x}

Pericom {4-Differential Channel, 2:1 Mux/DeMux, DVI/HDMI Compliant Signal Switch based on TMDS Signaling Standard, PI3HDMI412}

Texas Instruments, TI {DisplayPort to TMDS Translator, SN75DP129}

TranSwitch {High-speed TMDS repeater devices for DVI/HDMI digital video applications, TCX-4238x}

HDMI Cable
HDMI Cable

HDMI Connector Pinout
Pin Number Signal name Pin Number Signal name
1 TMDS Data 2+ 20 SHELL
2 TMDS Data 2 Shield 19 Hot Plug Detect
3 TMDS Data 2- 18 +5V Power
4 TMDS Data 1+ 17 Ground
5 TMDS Data 1 Shield 16 DDC Data
6 TMDS Data 1- 15 DDC Clock
7 TMDS Data 0+ 14 No Connect
8 TMDS Data 0 Shield 13 CEC
9 TMDS Data 0- 12 TMDS Clock-
10 TMDS Clock+ 11 TMDS Clock Shield

HDMI Connector Manufacturers


Leoco {High Definition Media Input, HDMI Socket, HDMI Plug}

Molex {HDMI Connector Manufacturer}

Tyco Electronics {HDMI Connectors}

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Modified 2/4/12
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