HDMI 2.1a gains power directly to active HDMI cables

The HDMI Forum is adding to the new HDMI 2.1a specification, in the form of Cable Power. This function should make it easier to use longer active HDMI cables. Cables are supplied with power directly from the HDMI connection.

HDMI Forum introduces HDMI Power Cable in an amendment of the HDMI 2.1a specification† With this feature, active HDMI cables can be powered directly from the HDMI connection, without having to connect a separate power cable. This should simplify the use of active HDMI cables, argues the HDMI Forum. The feature allows cables to draw up to 300mA at 5V from the HDMI connection.

To use the feature, both a cable and a ‘source device’ that support HDMI Power Cable are required. HDMI Power Cable cables also receive a separate power connector for use with devices that are not compatible with the feature. According to the HDMI Forum, these will be USB-C or USB-Micro-B connections.

Active HDMI cables are mainly used to allow for longer cable lengths. With passive cables from certain lengths stability problems can occur due to signal loss. HDMI Power Cable should make using active HDMI cables as easy as connecting passive cables.