HDMI TFT

HDMI TFT

1.HDMI, also known as HD multimedia interface, is a full-digital video and audio transmission interface that can send uncompressed audio and video signals. HDMI can be used in STB, DVD players, personal computers, video game instruments, integrated amplifiers, digital stereos and televisions. HDMI can send audio and video signals at the same time. Since audio and video signals use the same cable, the installation of system circuit is greatly simplified.

2.Four HDMI interfaces are specified in the HDMI specification. They are:

HDMI A Type

It is used in the HDMI1.0 version and there are a total of 19pin with a size of 4.45mm×13.9mm, which is the most common HDMI connector. The phase-to-point transmission is DVI single-link. Before the advent of HDMI 1.2a, the maximum transmission capacity of TMDS was 165MHz, so the maximum transmission specification was only 1600×1200 (TMDS 162.0mhz).

Pin Pin definition
1 TMDS Data2+
2 TMDS Data2 Shield
3 TMDS Data2–
4 TMDS Data1+
5 TMDS Data1 Shield
6 TMDS Data1–
7 TMDS Data0+
8 TMDS Data0 Shield
9 TMDS Data0–
10 TMDS Clock+
11 TMDS Clock Shield
12 TMDS Clock–
13 CEC
14 Reserved（N.C. on device）
15 SCL
16 SDA
17 DDC/CEC Ground
18 +5V Power
19 Hot Plug Detect

HDMI B Type

It is used in the HDMI1.0 version. With a total of 29pin and a size of 4.45mm×21.2mm, it can transmit twice the amount of TMDS data of HDMI A type. Phase-to-point transmission on DVI dual-link is used for the transmission of high resolution (WQXGA 2560×1600 +). Since HDMI A type only has single-link TMDS transmission, it must have twice the transmission efficiency if it is to be transmitted as HDMI B type signal, which will cause the working frequency of Tx and Rx of TMDS must be increased to above 270MHz. Before the advent of HDMI 1.3IC, most Tx and Rx of TMDS in the market could only work stably under 165MHz. This type of interface has not been applied to any product yet.

Pin Pin definition
1 TMDS Data2+
2 TMDS Data2 Shield
3 TMDS Data2–
4 TMDS Data1+
5 TMDS Data1 Shield
6 TMDS Data1–
7 TMDS Data0+
8 TMDS Data0 Shield
9 TMDS Data0–
10 TMDS Clock+
11 TMDS Clock Shield
12 TMDS Clock–
13 TMDS Data5+
14 TMDS Data5 Shield
15 TMDS Data5-
16 TMDS Data4+
17 TMDS Data4 Shield
18 TMDS Data4-
19 TMDS Data3+
20 TMDS Data3 Shield
21 TMDS Data3-
22 CEC
23 Reserved（N.C. on device）
24 Reserved（N.C. on device）
25 SCL
26 SDA
27 DDC/CEC Ground
28 +5V Power
29 Hot Plug Detect

HDMI C Type

Commonly known as mini-HDMI, it is used in HDMI1.3 version . With a total of 19pin and a size of 2.42mm×10.42mm, it can be referred as a miniature version of HDMI A type, but its definition of foot position has been changed. It is mainly applied to portable devices, such as DV, digital cameras, portable multimedia players, etc. Due to size limitations, some graphics cards use mini-HDMI, thus users have to use a adapter to convert it to a standard-size Type A before connecting to the display.

Pin Pin definition
1 Hot Plug Detect
2 Utility
3 TMDS Data2+
4 TMDS Data2 Shield
5 TMDS Data2-
6 TMDS Data1+
7 TMDS Data1 Shield
8 TMDS Data1-
9 TMDS Data0+
10 TMDS Data0 Shield
11 TMDS Data0-
12 TMDS Clock+
13 TMDS Clock Shield
14 TMDS Clock-
15 CEC
16 DDC/CEC Ground
17 SCL
18 SDA
19 +5V Power

HDMI D Type

It is used in HDMI1.4 version. There are a total of 19 pins with a size of 2.8mm×6.4mm, and the foot position definition has been changed. The interface of  the new Micro HDMI is about 50% smaller than that of the current 19-pin MINI HDMI, and provides up to 1080p resolution support and up to 5GB transmission speed for portable devices such as cameras and mobile phones.