Dell Precision 7550 Service Manual page 12

it. A laptop might require up to 60 watts, for example. The USB Power Delivery specification ups this power delivery to 100 watts. It's bi-
directional, so a device can either send or receive power. And this power can be transferred at the same time the device is transmitting
data across the connection.
This could spell the end of all those proprietary laptop charging cables, with everything charging over a standard USB connection. You
could charge your laptop from one of those portable battery packs you charge your smartphones and other portable devices from today.
You could plug your laptop into an external display connected to a power cable, and that external display would charge your laptop as you
used it as an external display — all using the one little USB Type-C connection. To use this, the device and the cable have to support USB
Power Delivery. Just having a USB Type-C connection does not necessarily mean they do.
USB Type-C and USB 3.2
USB 3.2 is a new USB standard. USB 3's theoretical bandwidth is 5 Gbps, while USB 3.2's is 20 Gbps, that is, double the bandwidth as
fast as a first-generation Thunderbolt connector. USB Type-C is not the same thing as USB 3.2. USB Type-C is just a connector shape,
and the underlying technology could just be USB 2 or USB 3.0. In fact, Nokia's N1 Android tablet uses a USB Type-C connector, but
underneath it is all USB 2.0—not even USB 3.0. However, these technologies are closely related.
Thunderbolt over USB Type-C
Thunderbolt is a hardware interface that combines data, video, audio, and power in a single connection. Thunderbolt combines PCI
Express (PCIe) and DisplayPort (DP) into one serial signal, and additionally provides DC power, all in one cable. Thunderbolt 1 and
Thunderbolt 2 use the same connector as mini-DP (DisplayPort) to connect to peripherals, while Thunderbolt 3 uses a USB Type-C
connector.
Figure 1. Thunderbolt 1 and Thunderbolt 3
1. Thunderbolt 1 and Thunderbolt 2 (using a miniDP connector)
2. Thunderbolt 3 (using a USB Type-C connector)
Thunderbolt 3 over USB Type-C
Thunderbolt 3 brings Thunderbolt to USB Type-C at speeds up to 40 Gbps, creating one compact port that does it all - delivering the
fastest, most versatile connection to any dock, display, or data device like an external hard drive. Thunderbolt 3 uses a USB Type-C
connector/port to connect to supported peripherals.
1. Thunderbolt 3 uses USB Type-C connector and cables - It is compact and reversible.
2. Thunderbolt 3 supports speed up to 40 Gbps.
3. DisplayPort 1.4 – compatible with existing DisplayPort monitors, devices, and cables.
4. USB Power Delivery - Up to 130 W on supported computers.
Key Features of Thunderbolt 3 over USB Type-C
1. Thunderbolt, USB, DisplayPort, and power-on USB Type-C on a single cable (features vary between different products).
2. USB Type-C connector and cables which are compact and reversible.
3. Supports Thunderbolt Networking (*varies between different products).
4. Supports up to 4 K displays.
5. Up to 40 Gbps
12 Technology and components