Manufacturers rally behind mobile HDMI variant

Nokia, Samsung, Toshiba and Sony want to make MHL technology a standard. The technology makes it possible to send HD content from a phone to an HD screen via a cable and would offer advantages over HDMI.

Nokia, Samsung, Sony and Toshiba have supported the mobile high-definition link-technology from Silicon Image grouped† Together with Silicon Image, the companies want to ensure that the technology becomes a widely supported standard. The MHL technology has been developed to be able to send HD images from a mobile device to a screen. The mobile device can simply be connected to the HDMI input of the TV via the MHL cable, but the television must be able to process the MHL signals. Televisions that can do that are not yet available, so when the first mobiles with an MHL input appear, a docking station will have to be used to convert the images to HDMI.

Support for MHL is included in the HDMI 1.4 specification, and the first chips for this version of the HDMI standard were announced in July. The technology can be seen as the mobile brother of hdmi, where Silicon Image is one of the driving forces behind. The reason for a separate standard for the transmission of ‘mobile’ HD signals would be that on many devices there is no room for an HDMI connector: it usually consists of nineteen pins. Thin phones in particular would not have room for this. The mhl interface is a lot smaller with five pins.

An MHL chip would also be more energy efficient than an HDMI chip, which is important in connection with the battery life. The chips would consume 0.04W in active state. According to Silicon Image, an HDMI chip quickly consumes ten times as much. In addition, the MHL input can be used to charge the device, for example with the docking station.