|
What is MHL?
MHL is an audio/video interface that connects portable consumer electronics devices such as mobile phones, digital cameras, camcorders and portable media players to HDTVs using a single cable via the standard HDMI input port. MHL technology was developed by Silicon Image, Inc., developer of the HDMI specification and the world’s leading manufacturer of HDMI semiconductors and intellectual property.
How will consumers benefit from MHL technology?
A tremendous amount of multimedia content is downloaded, captured and/or stored on portable personal entertainment devices, from high-resolution images and short videos to feature-length Hollywood films. However, when consumers connect their mobile devices to an HDTV via standard analog connections, the picture is displayed with poor image quality, often below standard definition. MHL equipped devices connect to HDTVs via a standard HDMI port so users can watch and listen to their digital content on a large screen in high definition. Since HDMI is already entrenched as the de facto interface standard for HDTVs, consumers can be assured their new mobile devices will be 100% compatible with over 200 million DTVs worldwide, now and for years to come.
How is MHL technology implemented in mobile CE devices?
To equip a mobile device with MHL technology, the manufacturer would add an MHL transmitter IC to the mobile device. Four pins on the device’s connector needs to be reserved for audio/visual Transition Minimized Differential Signaling (TMDS) packets and a single pin is reserved for a control bus, which supports content protection authentication, A/V format discovery and Consumer Electronics Control (CEC).
MHL equipped devices connect to the DTV via a docking station or dongle, which includes an MHL bridge IC that performs the conversion from the lossless MHL media format into a standard HDMI compatible signal. The docking station is equipped with a standard HDMI output connector, allowing the docking station to be plugged directly into HDTVs. The docking station can pass AC power through to the mobile device to charge the battery when the device is in the dock and a USB connector will allow the device to exchange data with a PC.
Why not just equip the mobile device with HDMI output?
Portable mobile devices such as digital cameras, portable media players and mobile phones have connector size limitations and generally opt to have a single proprietary connector that accommodates AC power, USB and audio/video transfer. The standard HDMI interface would require 19 pins on this connector, which often makes HDMI difficult to implement on small devices. MHL technology reduces this pin-count requirement from 19 to five, without compromising audio/video quality or HDMI compatibility.
In addition to size limitations, battery life is an important factor for portable CE devices. Playback time is an important feature that significantly influences many consumers’ purchase decisions. The low active and standby power consumption of MHL transmitters dramatically extend battery life in mobile devices. In the active setting at 720p and 1080i, the transmitters consume no more than 35 milliwatts (mW), an industry low. On standby mode, the transmitters consume just 20 microwatts (µW). These MHL transmitter power draw specifications are typically 10x lower than typical HDMI transmitters.
Why not just use an analog connection between the dongle and the HDTV?
Component video requires three video connectors plus stereo audio connectors or a multi-channel audio optical connector, for a total of five to six connectors. This puts a burden on the manufacturer to integrate a larger dock connector. In some cases, manufacturers have implemented a serial dock interface for the compressed media and then decoded the media using a digital signal processor in the dock, an expensive solution duplicating the functions in the mobile device. MHL solves this problem with a low-cost, low-pin count interface.
In Summary, what are the key features of MHL technology?
- MHL technology provides HD audio/video with only five pins, allowing a tiny connector suitable for portable devices;
- MHL technology conserves battery life with ultra-low active and standby power draw;
- MHL technology supports high-quality digital HD audio and video with resolutions up to 1080p;
- MHL technology is 100% compatible with the over 200 million HDMI-equipped DTVs worldwide today and the estimated 400 million by 2011;
- MHL technology includes integrated CEC functions and arbitration logic;
- MHL technology provides manufacturing flexibility by supporting MIPI DSI or parallel RGB input
What products that support MHL Technology are available?
MHL Transmitters are low pin-count digital media transmitters featuring a single data lane Transition Minimized Differential Signaling (TMDS) solution, which reduces pin count for small devices. These transmitters can deliver full high-definition (HD) video and digital audio through five pins on miniature connectors. When combined with an MHL bridge, MHL transmitters form an HDMI-enabled source device fully compliant to HDMI compliance test specifications. MHL Transmitters are available with support for Mobile Industry Processor Interface (MIPI) input or parallel RGB digital video input. The low active and standby power consumption of MHL transmitters extend battery life in mobile devices.
VastLane SiI9220 MHL Transmitter with MIPI Input Interface
VastLane SiI9222 MHL Transmitter with Parallel RGB Input Interface
MHL-to-HDMI bridges convert an MHL equipped device’s audio and video signals into a standard HDMI signal. The MHL bridge provides a cost-effective solution for a docking station or dongle that is fully HDMI compatible.
VastLane SiI9290 MHL-to-HDMI Bridge
Silicon Image: a Market Leader
Silicon Image developed the MHL technology specification and was
first-to-market with MHL products that will have a tremendous impact on
the way mobile devices are used to consume media. MHL technology will
allow consumers to enjoy digital content on large screens - when and
where they want - in high definition. Silicon Image continues to lead
the way in innovation and in delivering the most advanced mobile
solutions in HD content. Click the links below to learn more about
VastLane MHL semiconductors or contact a Silicon Image sales
representative to order a starter kit today.
VastLane SiI9220 MHL Transmitter with MIPI Input Interface
VastLane SiI9222 MHL Transmitter with Parallel RGB Input Interface
VastLane SiI9290 MHL-to-HDMI Bridge
 |