Will mobile phone designers adopt all of the available features in the universal serial bus (USB) Type-CTM specification? Probably not. They’ll weigh their options against the impact on overall product cost. The new USB Type-C interface comes with ultra-thin connectors that are less than 3mm high and 8.4mm wide, making it ideal for mobile phones. USB Type-C offers a cable-and-plug assembly that is “flippable” and reversible. The interface provides options for data and video up to 20Gbps and power up to 100W.
Figure 1: USB Type-C full-featured cable
The USB Type-C interface supports USB 2.0 and 3.1 data and 15W (5V, 3A) power charging natively using a channel configuration (CC) function. The optional USB Power Delivery (USB PD) function enables video such as DisplayPort and power charging up to 100W (20V, 5A).
While USB On-The-Go (OTG) allows mobile phones to assume dual data roles – a host or a client device – USB Type-C introduces a mode called dual role port (DRP) that allows it to have dual roles for both data and power. DRP means that the port can either assume the downstream facing port (DFP) role as the USB host and power provider or the upstream facing port (UFP) role as the USB device and power consumer. As a result, a mobile phone with DRP can get power for charging when connected to a laptop or in turn provide power to a flash drive. USB PD further enables independent data and power roles so that an upstream data port can provide power and a downstream data port can sink power.
As I mentioned earlier, engineers must decide if different USB Type-C features are worth the trade-offs and potential increased cost. Some of the trade-offs may include:
See Table 1 for USB Type-C options for system implementations.
Table 1: USB Type-C options with a native CC controller versus USB-PD
TI’s TUSB320 is a single-chip CC controller solution for mobile phones with USB 2.0 data and 15W of power support. The device provides optional features such as Try.SNK, audio/debug accessory detection, dead battery support and ID emulation for flexible system implementations. Note that two DRPs connected together result in a random power provider/consumer relationship unless the phone becomes a power consumer using the Try.SNK feature. The Try.SNK feature could be useful to avoid situations where a phone starts charging a notebook.
If you are in need of a solution that supports both power and data requirements, TI’s TUSB321 and HD3SS3212 together can provide a USB Type-C solution that provides USB 3.1 for data and 15W for power. The TUSB321 is a CC controller with VCONN power output (required per USB Type-C specs) to support active cables. The HD3SS3212 is a USB SuperSpeed mux supporting USB 3.1 Gen 1 and 2.
TI’s TUSB320, TUSB321 and HD3SS3212 meets USB Type-C Specification 1.1 Engineering Change Notices as of June 22, 2015. In addition, we’re early leaders in interoperability, providing the most robust solution for the USB Type-C ecosystem.
What would you like to know about USB Type-C in future blog posts? Let me know by leaving a comment below.
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