Does DisplayPort Carry Power?

DisplayPort (DP) continues to feature in more and more devices. Admittedly, it offers a ton of video quality goodness. And there’s every likelihood that, moving forward, it will be standard on most devices.

As we become more familiar with DP on TVs and displays and not just on computers, there’s a lot we should know about this interface.

For example, does DisplayPort carry power? And can we use it to charge our gadgets? Read on to discover this and more about DisplayPort.

Does DisplayPort carry power?

DisplayPort carries a small amount of power, with the sole objective of charging the cables and adapters connecting to the DisplayPort device. It only supplies 3.3V, an amount that is less than the voltage required to charge small devices, like smartphones, tablets, and USB hubs.

DisplayPort does include a power pin, DP_PWR, which is what supplies the 3.3V at 500mA. 

By any count, this is not massive power. And it’s intended to power small components that are necessary to complete the connection between devices.

Specifically, the pin only powers:

• Active cables that connect devices across greater distances
• Hybrid cables
• Display adapters
• And display hubs like the Multi-Stream Transport (MST)

It does not have enough voltage to power devices, whether smartphones, laptops, cameras, and other media players.

By contrast, an electrical cable with a 0.5 square mm conductor carries a minimum of 3 amps of electric power, an equivalent of 26.67V.

That’s quite a jump from what the 3.3V DisplayPort carries to the 26.6V of a small-capacity power cable. And it makes the distinction that one (the power cable) has the internal workings to supply power, and the other (the DisplayPort) does not.

The primary duty of the DP interface is to transport video signals. For the DP cable to carry enough energy to power equipment, it would require circuitry similar to the one used in electrical cabling. 

It would also require a different structure and layout, including a metal core, insulation, and sheathing. As it is, however, DP cables have a different configuration.

Can DisplayPort 1.4 carry power?

DisplayPort 1.4 carries a limited amount of power, just like all other DisplayPort versions. 

The power it provides is only enough to charge cables connecting to the DisplayPort port. It will not charge larger devices you may wish to connect to the DisplayPort device.

Going by the many questions spread across the Internet , there’s quite a bit of confusion on whether DisplayPort 1.4 powers devices. But even more interesting is that a sizable number of web users say it does. 

How did this presumption come up?

One might say that this confusion has something to do with the Multi-Stream Transport (MST), which made its debut in DisplayPort version 1.2. 

We must put a disclaimer here and say that this is a mere assumption, not documented fact. And one could come to this conclusion after analyzing the answers that users give about DisplayPort power capacity.

Now, back to MST.

The MST update made it possible to link multiple displays to a single DisplayPort device. And because Displayport supplies enough power to run the average MTS hub, many of us naturally assumed that the interface could charge different devices.

But that’s not true, as Page 22 of this DisplayPort User Guide from VESA shows.

Maybe the uncertainty abounds because DisplayPort isn’t as mainstream as, say, HDMI (yet). And therefore, not very many have a solid experience using it and a sound understanding of how it works.

Does Mini DP supply power?

Mini DP works just like DisplayPort, its primary function being a video connection port. However, it does not supply electrical power to devices.

Nonetheless, it carries a maximum of 0.5 A, an amount small enough to supply power to a cable but not a device.

That means if you connect a source and a recipient via a Mini DisplayPort cable, the Mini DP port connector will supply sufficient power to transport the signal to the receiving device. 

Likewise, when you connect two devices using an adapter, the Mini DP source device provides enough power, which the adapter then uses to process the signal.

But you cannot connect a notebook to the DisplayPort port of your PC, for instance, and hope that the PC will power the notebook. DisplayPort does not carry enough power to do that.

Can you charge from DisplayPort?

The only devices you can charge from a DisplayPort port are cables, adapters, and display hubs.  

Most electronic devices draw much more power than DisplayPort can provide. 

So connecting any of them to your computer, monitor, or TV DisplayPort port in the hope that the DP device will power them is a tall order. Like an attempt at building castles in the air, it’s not going to happen.

The USB-C connection

DisplayPort on USB Type-C—or Alternate mode (Alt Mode)—is a DP standard that transmits DisplayPort signals over the USB-C interface. But it does plenty more. 

This DisplayPort standard also offers Superspeed USB, backward compatibility with HDMI, VGA, and DVI via adapters and adapter cables, and USB Power Delivery. 

The latter, USB PD, has a power capacity of up to 100 watts. But currently, PD only supplies power to chargers and maybe battery packs.

If your device has DisplayPort Alt Mode, you will benefit from the power capabilities of the USB-C interface. However, that only happens when you connect the USB-C cable directly from the DisplayPort source to a DisplayPort Alt Mode or USB-C display. 

If you’re connecting two devices with different file formats and connectors, you’ll use an adapter. Unfortunately, plugging an adapter between the cable and the port means you lose out on DisplayPort Over USB-C Power Delivery.

Conclusion

The DisplayPort interface carries a minimal amount of power for the sole reason of powering cables and adapters connected to it. 

And so does Mini DisplayPort. 

It supplies just enough power for connected cables and adapters to tap into when transporting and processing video signals.

Because of that, you cannot use DP/Mini DP ports and cables to power electronic devices.

Not to mention, the smallest electronic devices need at least 5V to run. And this is far beyond the voltage capacity of DisplayPort and Mini DisplayPort.