Dell Precision 5540 Service Manual - Page 14

USB Power Delivery The USB PD specification is also closely intertwined with USB Type-C. Currently, smartphones, tablets, and other mobile devices often use a USB connection to charge. A USB 2.0 connection provides up to 2.5 watts of power - that'll charge your phone, but that's about 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 bidirectional, 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 via 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 via 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 doesn't necessarily mean they do. USB Type-C and USB 3.1 USB 3.1 is a new USB standard. USB 3's theoretical bandwidth is 5 Gbps, while USB 3.1 Gen2 is10Gbps . That's double the bandwidth, as fast as a first-generation Thunderbolt connector. USB Type-C isn't the same thing as USB 3.1. 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's all USB 2.0 - not even USB 3.0. However, these technologies are closely related. USB features Universal Serial Bus, or USB, was introduced in 1996. It dramatically simplified the connection between host computers and peripheral devices like mice, keyboards, external drivers, and printers. Let's take a quick look on the USB evolution referencing to the table below. Table 10. USB evolution Type USB 2.0 Data Transfer Rate 480 Mbps Category High Speed Introduction Year 2000 USB 3.0/USB 3.1 Gen 5 Gbps 1Port Super Speed 2010 USB 3.1 Gen 2 10 Gbps Super Speed 2013 USB 3.0/USB 3.1 Gen 1 (SuperSpeed USB) For years, the USB 2.0 has been firmly entrenched as the de facto interface standard in the PC world with about 6 billion devices sold, and yet the need for more speed grows by ever faster computing hardware and ever greater bandwidth demands. The USB 3.0/USB 3.1 Gen 1 finally has the answer to the consumers' demands with a theoretically 10 times faster than its predecessor. In a nutshell, USB 3.1 Gen 1 features are as follows: • Higher transfer rates (up to 5 Gbps) • Increased maximum bus power and increased device current draw to better accommodate power-hungry devices • New power management features • Full-duplex data transfers and support for new transfer types • Backward USB 2.0 compatibility • New connectors and cable The topics below cover some of the most commonly asked questions regarding USB 3.0/USB 3.1 Gen 1. 14 Technology and components