The HDMI Licensing Administrator has announced an amendment to the HDMI 2.1a specification, adding a new feature known as “HDMI Cable Power”. The new spec is designed to support much longer HDMI cables than what exist today, without the need to add a separate power connector.
The feature is designed to overcome a key limitation of HDMI 2.1’s Fixed Rate Link signalling system, which can only carry super-fast and high-bandwidth signals over very short distances. As a result of this limitation, passive HDMI cables can only be a few, short metres in length.
Users have overcome this with the use of “active HDMI” cables, which rely on amplifiers to boost the signal so it can be maintained over a longer distance. However, these are generally only used in professional settings. One of the drawbacks of active HDMI cables though is that they require their own power supply. HDMI Cable Power overcomes this, drawing up to 300 mA of power from a 5V supply directly through the HDMI connector.
The result will be longer cables and a less convoluted cable run in home cinema setups, FlatpanelsHD suggested.
The future, longer HDMI Cable Power Cables will be one-directional with a specified source and output. The HDMI website explains that one end will be lablled as the HDMI Source, and the other as the HDMI Sink, meaning that the cables won’t work in reverse.
The new HDMI Cable Power spec will be made available for all types of HDMI cable, but for those interested in ARC and eARC support, they’ll need to look for an Ultra High-Speed HDMI Cable, Premium High-Speed HDMI Cable with Ethernet, High-Speed HDMI Cable with Ethernet or Standard HDMI Cable with Ethernet.
Users will also be required to use a HDMI source device that supports the new HDMI Power Cable feature. Unfortunately, it doesn’t seem as if any products currently available do support the new feature yet.
