HDMI Cable Power removes the need for a separate power connector for active HDMI cables

Tudor Cibean

Posts: 140   +9
Staff
TL;DR: Longer active HDMI cables usually have a micro USB or USB-C connector to supply power to the internal chipset used for signal boosting. These ports won't be needed anymore if you get a cable and a source device that are both certified to support HDMI Cable Power.

The HDMI Forum has just announced a new amendment to its HDMI 2.1a standard. It adds support for HDMI Cable Power, which will allow active cables to draw power directly from the connector without needing a separate power cable.

Passive HDMI 2.0 cables can extend over 10 meters while maintaining support for the maximum bandwidth. The newer HDMI 2.1 spec almost tripled the maximum net data transfer rate, but that comes at a cost. Currently, the best passive cables that support the full 48 Gbps can reach about 3 meters before they run into difficulties with signal attenuation.

If you need to go further than that, active cabling is the answer. These have chips and retimers inside of them working together to reduce signal jitter. Standard HDMI cables are rated to carry up to 50 mA, which usually isn't enough to power their internal circuitry.

HDMI Cable Power raises that limit to 300 mA at 5V, eliminating the need for a separate USB connector for power. Essentially, active cables with HDMI Cable Power support will plug in just like passive cables, except they'll be unidirectional, with one end only plugging into the source and the other only into the display.

Finally, the source device has to support the HDMI Cable Power spec as well. The HDMI Forum says that consumers should check a device's specifications or packaging to determine whether the feature is supported.

Permalink to story.

 

Dimitriid

Posts: 2,217   +4,269
Or you could just use display port over USB-C and also carry enough power.

I seriously wish that once USB 4 gains speed we can just move away from hdmi altogether: One cable will be doing enough power, bandwidth, ethernet and video so there would be no good reason why any and all devices should just implement USB 4.
 

donnieD

Posts: 19   +15
Or you could just use display port over USB-C and also carry enough power.

I seriously wish that once USB 4 gains speed we can just move away from hdmi altogether: One cable will be doing enough power, bandwidth, ethernet and video so there would be no good reason why any and all devices should just implement USB 4.

One cable to rule them all...
 

bviktor

Posts: 946   +1,380
Or you could just use display port over USB-C and also carry enough power.

I seriously wish that once USB 4 gains speed we can just move away from hdmi altogether: One cable will be doing enough power, bandwidth, ethernet and video so there would be no good reason why any and all devices should just implement USB 4.
IKR? HDMI needs to die a swift death. Patent-protected proprietary cr@p.
 

Bao Nguyen

Posts: 117   +88
Or you could just use display port over USB-C and also carry enough power.

I seriously wish that once USB 4 gains speed we can just move away from hdmi altogether: One cable will be doing enough power, bandwidth, ethernet and video so there would be no good reason why any and all devices should just implement USB 4.

I concur. They should hurry up and remove all different kind of cables leave the one and only USB-C for all display connections.
 

Badvok

Posts: 350   +180
Or you could just use display port over USB-C and also carry enough power.

I seriously wish that once USB 4 gains speed we can just move away from hdmi altogether: One cable will be doing enough power, bandwidth, ethernet and video so there would be no good reason why any and all devices should just implement USB 4.
While HDMI certainly has issues it allows much higher data rates, and with this adjustment much longer cable lengths than USB 4 ever will. It would be nice to think we could have one standard cable for all connectivity but I think that is just a pipe dream.
 

Dimitriid

Posts: 2,217   +4,269
While HDMI certainly has issues it allows much higher data rates, and with this adjustment much longer cable lengths than USB 4 ever will. It would be nice to think we could have one standard cable for all connectivity but I think that is just a pipe dream.
It's why I specified display port over USB-C.
 

godrilla

Posts: 491   +244
It's why I specified display port over USB-C.
USB gen 4 caps out at 40 Gbps so technically can support dp 2.0 UHBR10 with 40 Gbps bandwidth.
Hdmi 2.1 at 48 Gbps and DP 2.0 with UHBR 20 at 80 Gbps will still be superior but anything less could be standardized to one cable until future usb successions.
 

Dimitriid

Posts: 2,217   +4,269
USB gen 4 caps out at 40 Gbps so technically can support dp 2.0 UHBR10 with 40 Gbps bandwidth.
Hdmi 2.1 at 48 Gbps and DP 2.0 with UHBR 20 at 80 Gbps will still be superior but anything less could be standardized to one cable until future usb successions.
Display Port 2.X can also be used over usb-c too at full speed, not just 40 gbps bandwidth not sure why you're thinking "converting" a display port signal to just USB 4 speeds when display port over usb-c is a different protocol altogether, look up usb-c alt mode.
 

godrilla

Posts: 491   +244
Display Port 2.X can also be used over usb-c too at full speed, not just 40 gbps bandwidth not sure why you're thinking "converting" a display port signal to just USB 4 speeds when display port over usb-c is a different protocol altogether, look up usb-c alt mode.
source club 3d website May 2022 article
DisplayPort™ Over USB C Technical Details

DisplayPort™ leverages the Alternate Mode Functional Extension of the USB Type-C interface, and shares similar electrical characteristics with USB 3.1, allowing use of common system elements.

  • Video, SuperSpeed USB and power, all on one connector
  • 4K @60Hz 24-bit color (without compression) with simultaneous USB 3.1
  • 5K (5120 x 2880) display support without compression with simultaneous USB 2.0
  • Support for BT.2020 color space, HDR, and HDCP 2.2
  • 8K x 4K display support with use of 4:2:0 pixel structure (good) or VESA Display Stream Compression (better)
  • High-end multichannel audio support
  • Backward compatible with VGA, DVI, and HDMI 2.0 with CEC using plug adapters or adapter cables
  • Extensible packet-based data structure
  • DisplayPort Alternate Mode (DP Alt Mode) with DP 1.4 support
what am I missing?
 

Dimitriid

Posts: 2,217   +4,269
You're missing this, should show how display port alt mode for USB 4 will support 80 gbps bandwidth, not just 40
 

godrilla

Posts: 491   +244
You're missing this, should show how display port alt mode for USB 4 will support 80 gbps bandwidth, not just 40
Nice Thank you. The longest one I was able to find is 6.6 feet.