GTrusted

Lenovo has recently launched the Yoga 920 (2-in-1) convertible notebook PC that provides dual Thunderbolt 3 enabled USB Type-C connectors. These Thunderbolt 3 ports support USB Power Delivery technology to rapidly charge the notebook, allowing external docks like the USB Power Delivery based Henge Docks Stone to be connected. While the Stone was initially made to support USB Type-C based Mac's, it should be able to work with certain non-Mac notebook PC's including the Yoga 920 (2-in-1). We find out here how well it supplies power over USB Power Delivery when plugged in to a  Thunderbolt 3 port on the Lenovo notebook.  

Note that only the USB Type-C port at the side of the Stone supports USB Power Delivery based charging which we connect it with the upstream Yoga 920 (2-in-1). Since the Stone claims to offer up to 87W of power through this USB-C port, we confirm using Granite River Labs GRL-USB-PD-A1 test  analyzer software while the Yoga 920 (2-in-1) is 52% charged.

At the start of the USB Power Delivery protocol transactions, we can see a soft reset happens to subsequently trigger multiple strings of Vendor Defined Messages to adjust voltage and current. The Stone later follows up to declare an initial power capability of 15 watts (5 volts @ 3 amps).

The Yoga 920 (2-in-1) proceeds to make a first power request of only 7.5 watts (5 volts @ 1.5 amps).

A hard reset then comes on to result in Vendor Defined Messages to exchange power ID's that again leads to the Stone advertising 15 watts (5 volts @ 3 amps) as seen earlier.

Once again we observe the Yoga 920 (2-in-1) repeats its initial 7.5 watts (5 volts @ 1.5 amps) request which finally gets accepted by the Stone. 

After a series of events including Power Role Swap, soft reset and Vendor Defined Messages occur, we can see the Stone eventually offers full power profiles of 15 watts (5 volts @ 3 amps), 36 watts (12 volts @ 3 amps), and 87 watts (20 volts @ 4.36 amps).

The Yoga 920 (2-in-1) can take advantage of the higher power available to request 65 watts (20 volts @ 3.25 amps) which the dock also complies.

After a soft reset, the PC and dock then start to communicate over a long list of Vendor Defined Messages which in between also shows DisplayPort Alt Mode being supported. 

When the Yoga 920 (2-in-1) is first plugged in at 52% battery level and during power on, it starts off pulling current which rapidly changes over the 65W power request and Vendor Defined Messages at initial voltage of around 20.3 volts. The voltage and current eventually level out after the first 10 seconds to stabilize charging at around 61.7 watts (19.9 volts @ 3.1 amps).

We can confirm that the Yoga 920 (2-in-1) uses USB Power Delivery well to charge effectively with the Stone at almost the max 65W that the notebook can similarly expect to get from its own 65 watts based Lenovo's supplied charger accessory. It's also good to see that the Stone is able to support not only USB Type-C based Mac's but also certain Thunderbolt 3 enabled Windows PC's like the Yoga 920 (2-in-1) using USB Power Delivery.