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diff --git a/chromium/docs/website/site/chromium-os/cable-and-adapter-tips-and-tricks/index.md b/chromium/docs/website/site/chromium-os/cable-and-adapter-tips-and-tricks/index.md deleted file mode 100644 index 574b18da7de..00000000000 --- a/chromium/docs/website/site/chromium-os/cable-and-adapter-tips-and-tricks/index.md +++ /dev/null @@ -1,177 +0,0 @@ ---- -breadcrumbs: -- - /chromium-os - - Chromium OS -page_name: cable-and-adapter-tips-and-tricks -title: USB Type-C Cable and Adapter Tips and Tricks ---- - -This page provides reference information for manufacturers of USB-C parts. It -addresses common misunderstandings and errors in building legacy cables (Type-A -or microB to USB-C) and power adapters. For complete specifications, tolerances -and application rules, see the latest version of the [USB Type-C -specification](http://www.usb.org/developers/docs/). - -## Legacy Cables - -The following table describes the type of resistor and configuration (pull-up or -pull-down) that is required for each type of legacy cable. All cables must be -capable of supporting 3A, regardless of Rp/Rd. - -<table> -<tr> -<td>**Resistor Rp (pull-up between VBUS and CC)**</td> -<td>**Resistor Rd (pull-down between CC and GND)**</td> -<td>**ID Pin**</td> -<td>**USB-C Spec Section**</td> -</tr> -<tr> -<td>USB Type-C plug to USB 3.1 Type-A plug</td> -<td>56 kΩ Rp</td> -<td>Open</td> -<td>Section 3.5.1</td> -</tr> -<tr> -<td>USB-C plug to USB 2.0 Type-A plug</td> -<td>56 kΩ Rp</td> -<td>Open</td> -<td>Section 3.5.2</td> -</tr> -<tr> -<td>USB-C plug to Type-A receptacle</td> -<td>Open</td> -<td>5.1 kΩ Rd</td> -<td>Section 3.6.1</td> -</tr> -<tr> -<td>USB-C receptacle to microB plug</td> -<td>Not allowed per the spec</td> -<td>Section 2.2</td> -</tr> -<tr> -<td>USB-C plug to microB plug</td> -<td>Open</td> -<td>5.1 kΩ Rd</td> -<td>unconnected</td> -<td>Section 3.5.7</td> -</tr> -<tr> -<td>USB-C plug to microB receptacle</td> -<td>56 kΩ Rp</td> -<td>Open</td> -<td>unconnected</td> -<td>Section 3.6.2</td> -</tr> -</table> - -### Cable FAQ - -* **My legacy cable conforms to the specification and is rated for 3A. - Can I use the Rp 3A resistor?** - * No. You must use the 56 kΩ Rp. The resistor indicates the - capability of the power adapter, not the capability of the - cable. It is not safe to use the 3A Rp: if the power adapter is - not capable of providing 3A it could overheat. -* **Why does my cable need to be rated for 3A if only the standard Rp - is used?** - * The standard Rp indicates that the power sink needs to use some - other method of finding what current the power source can - provide. This method could be BC1.2 or a proprietary discovery - scheme (such as the voltage set on D+/D-). Using these methods, - a sink could discover the source is capable of up to 3A. *All - cables must be capable of supporting 3A.* - -## Power Adapters - -For USB-C power adapters, the following table specifies the resistor type and -configuration. - -<table> -<tr> -<td>**Pull-up on CC1**</td> -<td>**Pull-up on CC2**</td> -<td>**VBUS**</td> -</tr> -<tr> -<td>5V 3A power adapter with USB-C receptacle</td> -<td>10 kΩ</td> -<td>10 kΩ</td> -<td>Cold</td> -</tr> -<tr> -<td>5V 1.5A power adapter with USB-C receptacle</td> -<td>22 kΩ</td> -<td>22 kΩ</td> -<td>Cold</td> -</tr> -<tr> -<td>5V 3A power adapter with captive USB-C cable</td> -<td>10 kΩ</td> -<td>open</td> -<td>Cold or Hot</td> -</tr> -<tr> -<td>5V 1.5A power adapter with captive USB-C cable</td> -<td>22 kΩ</td> -<td>open</td> -<td>Cold or Hot</td> -</tr> -</table> - -VBUS Cold : When nothing is attached to the USB-C receptacle or plug, VBUS must -be 0V or vSafe0V. 5V shall be applied to VBUS only when a UFP is detected by -monitoring voltage on the CC pin. 5V should only be applied when voltage vRd on -CC is 0.85V < vRd < 2.45V for a 3A power source. Please see Tables 4-23, -4-24, and 4-25 of the Type-C specification for the appropriate values of vRd -minimum and maximum voltages for Default USB Power, 1.5A, and 3.0A levels. - -VBUS Hot : When nothing is attached to the USB-C plug, 5V may be applied to -VBUS. - -Important Note : If your charger implements USB Power Delivery, regardless of -connector type (Receptacle or captive cable), VBUS Cold is required. - -### USB Battery Charging v1.2 - -For chargers with a USB-C receptacle, it is highly recommended the port also -support USB Battery Charging v1.2 in order to allow legacy devices using Type-A -plugs or Micro-B receptacles to charge. - -To implement a BC1.2 Dedicated Charging Port (DCP), D+ and D- lines in the -receptacle must be shorted together. Please see the [USB Battery Charging v1.2 -Spec](http://www.usb.org/developers/docs/devclass_docs/BCv1.2_070312.zip) for -more details on how to implement DCP or CDP. - -### USB PD Power Rules - -Power adapters with maximum power <= 15W may support USB Power Delivery. -Power adapters with maximum power > 15W must support USB Power Delivery. When -initially specifying the voltage and current capability of an adapter which -supplies > 15W, pay close attention to Power Rules, in USB PD R2.0 V1.2 -Section 10. - -[<img alt="image" -src="/chromium-os/cable-and-adapter-tips-and-tricks/SourcePowerRule.png">](/chromium-os/cable-and-adapter-tips-and-tricks/SourcePowerRule.png) - -USB PD Revision 2.0 specifies normative voltage rails of 5V, 9V, 15V, and 20V. -In order to support a particular voltage rail, all voltage rails lower must be -supported up to 3A. - -### Power Adapter FAQ - -* **In a 5V 3A or 5V 1.5A supply can I connect CC1 and CC2 and use a - single shared resistor?** - * No. This design fails with active cables, emarked cables or any - device that requests Vconn. These cables have an Ra pulldown on - one of the pins, preventing accurate detection of CC voltage if - the pins are shorted at the adapter. -* **May a Type-C charger support a proprietary method of changing - VBUS** in addition to or instead of USB Power Delivery? (For - example, Qualcomm QuickCharge, MediaTek PumpExpress, others) - * No. Section 4.8.2 of the USB Type-C Specification explicitly - forbids proprietary methods that change VBUS from the default - voltage defined by USB 2.0 and USB 3.1 specifications (maximum - 5.5V). This applies to both power sources and power sinks. If - the power adapter incorporates a Type-C plug or a Type-C - receptacle, that connector must not support any dynamic voltage - method other than USB Power Delivery.
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