HDMI A TO Right Angle MINI HDMI Cable

Principle analysis of hdmi cable

HDMI is a fully digital interface for the consumer electronics and PC sectors. It can transmit uncompressed audio signals and video signals. Because the audio and video signals are transmitted in the same cable, the number of interface cables is greatly simplified, and they are popular in home appliances and PC. Since its emergence, HDMI has developed several versions, ranging from HDMI 1.1 to HDMI 1.4. Although the appearance of the interface has not changed, but the function and bandwidth have been qualitatively improved. The mainstream HDMI interface version is HDMI 1.3 (A, B, C), but with the popularity of 3D video, a large number of HDMI 1.4 devices are launched, which become the key promotion products of various families. The HDMI 1.4 brings several innovative features, including the HDMI Ethernet channel, the audio return channel, the HDMI 3D video playback function, and the 4k2k ultra-high-resolution support. For cable, there was no HDMI version before. For example, the HDMI 1.1 and HDMI 1.3 cables are the same, but in HDMI 1.4, the cable has some changes. The HDMI version contains five types of cables, each with different functional and performance characteristics. HDMI 1.4 is divided into five versions: standard HDMI, standard HDMI with Ethernet, automotive HDMI, high speed HDMI, and high speed HDMI with Ethernet. Standard HDMI cables support 1080p, while high-speed HDMI support includes 4k2k, 3D video, dark color and other advanced display technologies. This line is actually the previous HDMI 1.3 version, and their bandwidth requirements are within the bandwidth provided by HDMI 1.3. But the high-speed HDMI with the Ethernet function also has a dedicated data channel, namely the HDMI Ethernet channel that provides the network function between the devices. The structure of the cable has changed, as it will be said later. The HDMI standards also specify the certification labels for these five types of cables. In this review sample, we also selected some cables called HDMI 1.4 version, but none of them strictly followed the HDMI standards. Usually the most common HDMI interface is type A with width of 13.9mm and a total of 19 pins, while there is a rare double-link type B interface with width of 21.2 mm, HDMI adopts four parallel TMDS differential signal channels, and the transmission link consists of 3 data channels and 1 clock channel. Three data channels are used to transmit the red, green, and blue data signals, and a fourth channel is used to transmit a clock, whose clock frequency is 1 / 10 of the data rate. Using the TMDS technology of HDMI, the common mode bias voltage of the differential signal is 3.3V, the port impedance is 50 ohm, the rated amplitude jumps to 500mV(2.8V~ 3.3V ~ 3.3 V), and the voltage swing amplitude varies from 150mV ~ 800mV. In addition, there are bidirectional communication signals transmitted through DDC (display data channel) data and clock lines, and HDCP (high-bandwidth digital copyright protection) signals in HDMI. The DDC bus is the key to HDMI compatibility.in compliance with