`
`
`
`
`Exhibit 2033
`
`Exhibit 2033
`
`

`

`Battery Charging Specification
`Revision 1.2
`December 7, 2010
`
`VIS EXHIBIT 2033
`
`

`

`Copyright © 2010, USB Implementers Forum, Inc.
`All rights reserved.
`
`A LICENSE IS HEREBY GRANTED TO REPRODUCE THIS SPECIFICATION FOR
`INTERNAL USE ONLY. NO OTHER LICENSE, EXPRESS OR IMPLIED, BY ESTOPPEL OR
`OTHERWISE, IS GRANTED OR INTENDED HEREBY.
`
`USB-IF AND THE AUTHORS OF THIS SPECIFICATION EXPRESSLY DISCLAIM ALL
`LIABILITY FOR INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS, RELATING
`TO IMPLEMENTATION OF INFORMATION IN THIS SPECIFICATION. USB-IF AND THE
`AUTHORS OF THIS SPECIFICATION ALSO DO NOT WARRANT OR REPRESENT THAT
`SUCH IMPLEMENTATION(S) WILL NOT INFRINGE THE INTELLECTUAL PROPERTY
`RIGHTS OF OTHERS.
`
`THIS SPECIFICATION IS PROVIDED "AS IS” AND WITH NO WARRANTIES, EXPRESS OR
`IMPLIED, STATUTORY OR OTHERWISE. ALL WARRANTIES ARE EXPRESSLY
`DISCLAIMED. NO WARRANTY OF MERCHANTABILITY, NO WARRANTY OF NON-
`INFRINGEMENT, NO WARRANTY OF FITNESS FOR ANY PARTICULAR PURPOSE, AND
`NO WARRANTY ARISING OUT OF ANY PROPOSAL, SPECIFICATION, OR SAMPLE.
`
`IN NO EVENT WILL USB-IF OR USB-IF MEMBERS BE LIABLE TO ANOTHER FOR THE
`COST OF PROCURING SUBSTITUTE GOODS OR SERVICES, LOST PROFITS, LOSS OF
`USE, LOSS OF DATA OR ANY INCIDENTAL, CONSEQUENTIAL, INDIRECT, OR SPECIAL
`DAMAGES, WHETHER UNDER CONTRACT, TORT, WARRANTY, OR OTHERWISE,
`ARISING IN ANY WAY OUT OF THE USE OF THIS SPECIFICATION, WHETHER OR NOT
`SUCH PARTY HAD ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.
`
`ii
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`

` Battery Charging Specification, Revision 1.2
`
`December 7, 2010
`
`Contributors
`Mark Lai
`Sammy Mbanta
`Abel Astley
`Kenneth Ma
`Shimon Elkayam
`Gaurav Singh
`Dan Ellis
`Graham Connolly
`Oscar Freitas
`Joel Silverman
`Pat Crowe
`Juha Heikkila
`Richard Petrie
`Sten Carlsen
`Jeroen Kleinpenning
`Terry Remple, Chair
`Dave Haglan
`Mark Bohm
`Morgan Monks
`Tim Knowlton
`Morten Christiansen
`Nicolas Florenchie
`Shaun Reemeyer
`George Paparrizos
`Adam Burns
`Wei Ming
`Jean Picard
`Ivo Huber
`Pasi Palojarvi
`Steven Tom
`Ed Beeman
`Mark Paxson
`
`Allion Test Labs
`Astec Power
`Broadcom
`Broadcom
`Broadcom
`Cypress
`DisplayLink
`Fairchild
`Fairchild
`Kawasaki
`MQP Electronics
`Nokia
`Nokia
`Nokia
`NXP Semiconductors
`Qualcomm
`SMSC
`SMSC
`SMSC
`SMSC
`ST Ericsson
`ST Ericsson
`ST Ericsson
`Summit Microelectronics
`Synopsys
`Telecommunication Metrology Center of MII
`Texas Instruments
`Texas Instruments
`Texas Instruments
`Texas Instruments
`USB-IF
`USB-IF
`
`iii
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`

`

` Battery Charging Specification, Revision 1.2
`
`
`Revision History
`Revision
`Date
`BC1.0
`Mar 8, 2007
`
`Author
`Terry Remple
`
`December 7, 2010
`
`
`BC1.1
`
`BC1.2
`
`Oct 5, 2010
`
`Terry Remple
`Adam Burns
`
`Description
`First release
`
`April 15, 2009 Terry Remple Major updates to all sections. Added Data Contact
`Detect protocol, and Accessory Charger Adapter.
`
`Following items indicate changes from BC1.1 to
`BC1.2. References below to Section, Figures and
`Tables refer to BC1.2, unless BC1.1 is specifically
`indicated.
`
`1. Allow DCPs to output more than 1.5A. Allows
`Portable Devices (PDs) with switch mode chargers to
`draw more power. Section 4.4.1.
`
`2. Increase minimum CDP current to 1.5A. Without
`change, PDs had to draw less than 500mA, to avoid
`CDP shutdown. Table 5-2.
`
`3. Indicate that ICDP max and IDCP max limits of 5A
`come from USB 2.0, and are safety limits. Table 5-2
`note 1.
`
`4. Allow PDs to draw up to 1.5A during HS chirp and
`traffic. Remove previous limits of 560mA and 900mA
`which was based on HS common mode ranges.
`Section 3.5.
`
`5. Require CDPs to support 1.5A during HS chirp and
`traffic. Affects CDP common mode range.
`Section 3.5.
`
`6. Reduce maximum PD current from 1.8A to 1.5A, to
`avoid shutdown when attached to CDP. Table 5-2.
`
`7. Rename Docking Station to ACA-Dock, to avoid
`confusion with other types of Docking Stations.
`
`8. Require ACA-Dock to differentiate itself from an
`ACA, by enabling VDM_SRC during no activity.
`Section 3.2.4.4.
`
`9. Allow CDP to leave VDM_SRC enabled while
`peripheral not connected. Section 3.2.4.2.
`
`10. Remove ICHG_SHTDWN. This was a recommended
`max output current for Charging Ports with VBUS
`grounded. BC1.1 Section 4.1.
`
`11. Require VDP_SRC to not pull D+ below 2.2V when
`D+ is being pulled to VDP_UP through RDP_UP.
`Require VDM_SRC to not pull D- below 2.2V when D- is
`being pulled high. Required for ACA-Dock support.
`Table 5-1 notes 1 and 2.
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`December 7, 2010
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`12. Make DCD current source optional for PDs.
`Section 3.2.3.
`
`13. Make DCD timeout required for PDs. Section
`3.2.3.
`
`14. Make Secondary Detection optional for PDs.
`Section 4.6.2.
`
`15. Make Good Battery Algorithm required behavior
`for PDs. Section 3.2.4.
`
`16. Remove resistive detection. BC1.1 Section 3.9.
`
`17. Change PD Required Operating Range to include
`4.5V at 500mA. Figure 4-3.
`
`18. Allow any downstream port to act as a DCP.
`Section 4.1.3.
`
`19. Require PDs to enable VDP_SRC or RDP_PU when
`charging from a DCP. Section 3.3.2.
`
`20. Allow chargers to renegotiate current with PD by
`dropping and reasserting VBUS. Section 4.1.3.
`
`21. Require PDs to discharge their own VBUS input
`after VBUS drops to support charger port
`renegotiation request. Section 4.6.3.
`
`22. Allow PDs to disconnect and repeat Charger
`Detection multiple times while attached, with specified
`timing. Section 4.6.3.
`
`23. Reduce DCP input impedance between D+, D- to
`VBUS and ground from 1M(cid:525) to 300k(cid:525). Section 4.4.3.
`
`24. Require CDPs to recover after over-current
`condition. Section 4.2.2.
`
`25. Allow greater DCP undershoot for large load
`current steps, to enable low quiescent current
`chargers required by Europe. Section 4.4.2.
`
`26. Define ACAs and ACA-Docks as types of
`Charging Ports. Section 1.4.5.
`
`27. Use session valid voltage range defined in EH
`and OTG Supplement rev 2.0. Section 3.2.2.
`
`28. Only devices that can operate stand-alone from
`internal battery power are allowed to use the Dead
`Battery Provision. Section 2.2.
`
`29. Allow compound PDs to draw ISUSP plus an
`
`
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`
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`December 7, 2010
`
`
`additional ISUSP for each downstream port.
`Section 2.1.
`
`30. Remove requirement for vendors to provide
`typical and maximum connect time for products
`having a Dead or Weak Battery for compliance
`testing. Section 2.
`
`31. Remove references to no battery from Dead
`Battery Provision. Section 2.
`
`32. Require PD using Dead Battery Provision to
`enable VDP_SRC from TDBP_ATT_VDPSRC after attach to
`TDBP_VDPSRC_CON before connect. Section 2.2.
`
`33. Added DBP – Configured Clause, which allows
`PD with Dead Battery to draw ICFG_MAX for
`TDBP_FUL_FNCTN without having to pass USBCV.
`Section 2.3.
`
`34. Note constraints when trying to charge from an
`OTG A-device. Section 1.6.
`
`35. Change IDP_SINK and IDM_SINK range from
`50-150uA to 25-175uA to ease PHY design. Table 5-2
`note 1.
`
`36. Allow USB 3.0 devices to implement BC charger
`detection protocols, and to use USB 3.0 ranges for
`IUNIT and ICFG_MAX. Section 1.7.
`
`37. Rename previous ACA to Micro ACA, and define
`the Standard ACA. Section 6.
`
`38. Add caps to OTG and Accessory Ports on ACA to
`support Attach Detection Protocol (ADP). Figure 6-3.
`
`39. Change ACA ID resistance tolerances from 5% to
`1% to ease PHY design. Table 5-3.
`
`40. Remove requirements on ACA switching
`time(TACA_ID_VBUS) to ease ACA design. BC1.1
`Section 6.5.
`
`41. Add state diagram for PDs attached to ACA.
`Section 6.2.7.
`
`42. Require PDs to limit current from ACA such that
`VBUS remains above VACA_OPR. Section 6.2.2.
`
`43. Change minimum ACA operating voltage
`(VACA_OPR) from 3.0V to 4.1V. Table 5-1.
`
`44. Remove requirement that ACA VBUS resistances
`(RACA_CHG_DIS) be greater than 10k when
`VBUS_CHG is greater than 6.5V. PDs are
`
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`December 7, 2010
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`
`responsible for protecting themselves against higher
`voltages on VBUS. BC1.1 Section 6.7.
`
`45. Require ACAs to continue providing power to OTG
`device from Charging Port, even if ground offsets or
`USB reset cause D- to go below VDAT_REF.
`Section 6.2.6.
`
`46. Change charger shutdown recovery time
`(TSHTDWN_REC) from 2 seconds to 2 minutes. Table
`5-5.
`
`47. Indicate that ACA-Dock is required to pull D+ to
`VDP_UP with RDP_UP when VBUS is asserted.
`Section 3.2.4.4.
`
`48. Remove statements regarding devices with
`multiple receptacles. Covered in Multiple Receptacle
`white paper at http://www.usb.org/developers/docs/.
`
`49. Improve readability by adding and updating
`drawings, re-structuring sections, and clarifying text.
`
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` Battery Charging Specification, Revision 1.2
`
`December 7, 2010
`
`
`
`Table of Contents
`1.(cid:3)
`Introduction ...................................................................................................................................................... 1(cid:3)
`1.1(cid:3) Scope ................................................................................................................................................. 1(cid:3)
`1.2(cid:3) Background ........................................................................................................................................ 1(cid:3)
`1.3(cid:3) Reference Documents ........................................................................................................................ 1(cid:3)
`1.4(cid:3) Definitions of Terms ............................................................................................................................ 2(cid:3)
`1.4.1(cid:3) Accessory Charger Adaptor .................................................................................................. 2(cid:3)
`1.4.2(cid:3) ACA-Dock ............................................................................................................................. 2(cid:3)
`1.4.3(cid:3) Attach versus Connect .......................................................................................................... 2(cid:3)
`1.4.4(cid:3) Charging Downstream Port .................................................................................................. 2(cid:3)
`1.4.5(cid:3) Charging Port ........................................................................................................................ 2(cid:3)
`1.4.6(cid:3) Dead Battery Threshold ........................................................................................................ 2(cid:3)
`1.4.7(cid:3) Dedicated Charging Port ...................................................................................................... 3(cid:3)
`1.4.8(cid:3) Downstream Port .................................................................................................................. 3(cid:3)
`1.4.9(cid:3) Micro ACA ............................................................................................................................. 3(cid:3)
`1.4.10(cid:3) Portable Device..................................................................................................................... 3(cid:3)
`1.4.11(cid:3) Rated Current ....................................................................................................................... 3(cid:3)
`1.4.12(cid:3) Standard ACA ....................................................................................................................... 3(cid:3)
`1.4.13(cid:3) Standard Downstream Port .................................................................................................. 3(cid:3)
`1.4.14(cid:3) USB Charger ......................................................................................................................... 3(cid:3)
`1.4.15(cid:3) Weak Battery Threshold ....................................................................................................... 3(cid:3)
`1.5(cid:3) Parameter Values ............................................................................................................................... 4(cid:3)
`1.6(cid:3) OTG Considerations ........................................................................................................................... 4(cid:3)
`1.7(cid:3) Super Speed Considerations ............................................................................................................. 4(cid:3)
`2.(cid:3) Dead Battery Provision .................................................................................................................................... 4(cid:3)
`2.1(cid:3) Background ........................................................................................................................................ 4(cid:3)
`2.2(cid:3) DBP – Unconfigured Clause .............................................................................................................. 4(cid:3)
`2.3(cid:3) DBP – Configured Clause .................................................................................................................. 5(cid:3)
`3.(cid:3) Charging Port Detection .................................................................................................................................. 6(cid:3)
`3.1(cid:3) Overview ............................................................................................................................................. 6(cid:3)
`3.2(cid:3) Charger Detection Hardware .............................................................................................................. 7(cid:3)
`3.2.1(cid:3) Overview ............................................................................................................................... 8(cid:3)
`3.2.2(cid:3) VBUS Detect ......................................................................................................................... 8(cid:3)
`3.2.3(cid:3) Data Contact Detect ............................................................................................................. 9(cid:3)
`3.2.4(cid:3) Primary Detection ............................................................................................................... 14(cid:3)
`3.2.5(cid:3) Secondary Detection .......................................................................................................... 22(cid:3)
`3.2.6(cid:3) ACA Detection .................................................................................................................... 25(cid:3)
`3.3(cid:3) Charger Detection Algorithms .......................................................................................................... 27(cid:3)
`3.3.1(cid:3) Weak Battery Algorithm ...................................................................................................... 27(cid:3)
`3.3.2(cid:3) Good Battery Algorithm ...................................................................................................... 29(cid:3)
`3.4(cid:3) Charger Detection Timing................................................................................................................. 31(cid:3)
`3.4.1(cid:3) Data Contact Detect Timing ................................................................................................ 31(cid:3)
`3.4.2(cid:3) Detection Timing, CDP ....................................................................................................... 34(cid:3)
`3.5(cid:3) Ground Current and Noise Margins ................................................................................................. 35(cid:3)
`4.(cid:3) Charging Port and Portable Device Requirements .................................................................................... 36(cid:3)
`4.1(cid:3) Charging Port Requirements ............................................................................................................ 36(cid:3)
`4.1.1(cid:3) Overshoot ........................................................................................................................... 36(cid:3)
`4.1.2(cid:3) Maximum Current ............................................................................................................... 36(cid:3)
`4.1.3(cid:3) Detection Renegotiation ..................................................................................................... 36(cid:3)
`4.1.4(cid:3) Shutdown Operation ........................................................................................................... 36(cid:3)
`4.1.5(cid:3) Failure Voltage .................................................................................................................... 36(cid:3)
`4.1.6(cid:3) Multiple Ports ...................................................................................................................... 36(cid:3)
`
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`4.2(cid:3) Charging Downstream Port .............................................................................................................. 37(cid:3)
`4.2.1(cid:3) Required Operating Range ................................................................................................. 37(cid:3)
`4.2.2(cid:3) Shutdown Operation ........................................................................................................... 37(cid:3)
`4.2.3(cid:3) Undershoot ......................................................................................................................... 38(cid:3)
`4.2.4(cid:3) Detection Signaling ............................................................................................................. 38(cid:3)
`4.2.5(cid:3) Connector ........................................................................................................................... 38(cid:3)
`4.3(cid:3) ACA-Dock ......................................................................................................................................... 38(cid:3)
`4.3.1(cid:3) Required Operating Range ................................................................................................. 38(cid:3)
`4.3.2(cid:3) Undershoot ......................................................................................................................... 38(cid:3)
`4.3.3(cid:3) Detection Signaling ............................................................................................................. 38(cid:3)
`4.3.4(cid:3) Connector ........................................................................................................................... 38(cid:3)
`4.4(cid:3) Dedicated Charging Port .................................................................................................................. 39(cid:3)
`4.4.1(cid:3) Required Operating Range ................................................................................................. 39(cid:3)
`4.4.2(cid:3) Undershoot ......................................................................................................................... 40(cid:3)
`4.4.3(cid:3) Detection Signaling ............................................................................................................. 40(cid:3)
`4.4.4(cid:3) Connector ........................................................................................................................... 40(cid:3)
`4.5(cid:3) Accessory Charger Adapter ............................................................................................................. 40(cid:3)
`4.5.1(cid:3) Required Operating Range ................................................................................................. 40(cid:3)
`4.5.2(cid:3) Undershoot ......................................................................................................................... 40(cid:3)
`4.5.3(cid:3) Detection Signaling ............................................................................................................. 40(cid:3)
`4.5.4(cid:3) Connector ........................................................................................................................... 41(cid:3)
`4.6(cid:3) Portable Device ................................................................................................................................ 41(cid:3)
`4.6.1(cid:3) Allowed Operating Range ................................................................................................... 41(cid:3)
`4.6.2(cid:3) Detection Signaling ............................................................................................................. 41(cid:3)
`4.6.3(cid:3) Detection Renegotiation ..................................................................................................... 42(cid:3)
`4.6.4(cid:3) Connector ........................................................................................................................... 42(cid:3)
`5.(cid:3) Parameter Values ........................................................................................................................................... 43(cid:3)
`6.(cid:3) Accessory Charger Adapter ......................................................................................................................... 48(cid:3)
`6.1(cid:3)
`Introduction ....................................................................................................................................... 48(cid:3)
`6.2(cid:3) Micro ACA ........................................................................................................................................ 49(cid:3)
`6.2.1(cid:3) Micro ACA Ports ................................................................................................................. 49(cid:3)
`6.2.2(cid:3) Micro ACA Connectivity Options ......................................................................................... 50(cid:3)
`6.2.3(cid:3) Micro ACA Architecture ...................................................................................................... 51(cid:3)
`6.2.4(cid:3) Micro ACA Modes of Operation .......................................................................................... 52(cid:3)
`6.2.5(cid:3)
`Implications of not Supporting Micro ACA Detection .......................................................... 53(cid:3)
`6.2.6(cid:3) Micro ACA Requirements ................................................................................................... 53(cid:3)
`6.2.7(cid:3) Portable Device State Diagram .......................................................................................... 55(cid:3)
`6.3(cid:3) Standard ACA ................................................................................................................................... 57(cid:3)
`6.3.1(cid:3) Standard ACA Ports ........................................................................................................... 57(cid:3)
`6.3.2(cid:3) Standard ACA Architecture ................................................................................................. 58(cid:3)
`6.3.3(cid:3) Standard ACA Modes of Operation .................................................................................... 59(cid:3)
`6.3.4(cid:3)
`Implications of not Supporting Standard ACA Detection .................................................... 60(cid:3)
`6.3.5(cid:3) Standard ACA Requirements ............................................................................................. 60(cid:3)
`
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` Battery Charging Specification, Revision 1.2
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`December 7, 2010
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` Battery Charging Specification, Revision 1.2
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`December 7, 2010
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`
`Figures
`Figure 3-1 System Overview ............................................................................................................................. 6(cid:3)
`Figure 3-2 Charger Detection Hardware ........................................................................................................... 8(cid:3)
`Figure 3-3 Data Pin Offset .............................................................................................................................. 10(cid:3)
`Figure 3-4 Data Contact Detect, Not Attached ............................................................................................... 11(cid:3)
`Figure 3-5 Data Contact Detect, Standard Downstream Port ......................................................................... 13(cid:3)
`Figure 3-6 Primary Detection, DCP ................................................................................................................ 14(cid:3)
`Figure 3-7 Primary Detection, CDP ................................................................................................................ 16(cid:3)
`Figure 3-8 Primary Detection, SDP ................................................................................................................. 18(cid:3)
`Figure 3-9 Primary Detection, ACA-Dock ....................................................................................................... 19(cid:3)
`Figure 3-10 Primary Detection, ACA ............................................................................................................... 21(cid:3)
`Figure 3-11 Secondary Detection, DCP .......................................................................................................... 23(cid:3)
`Figure 3-12 Secondary Detection, CDP .......................................................................................................... 24(cid:3)
`Figure 3-13 ACA Detection ............................................................................................................................. 26(cid:3)
`Figure 3-14 Weak Battery Algorithm ............................................................................................................... 27(cid:3)
`Figure 3-15 Good Battery Algorithm ............................................................................................................... 29(cid:3)
`Figure 3-16 DCD Timing, Contact After Start ................................................................................................. 31(cid:3)
`Figure 3-17 DCD Timing, Contact Before Start .............................................................................................. 32(cid:3)
`Figure 3-18 DCD Timing, No Contact ............................................................................................................. 33(cid:3)
`Figure 3-19 Detection Timing, CDP ................................................................................................................ 34(cid:3)
`Figure 4-1 CDP Required Operating Range ................................................................................................... 37(cid:3)
`Figure 4-2 DCP Required Operating Range ................................................................................................... 39(cid:3)
`Figure 4-3 Portable Device Allowed Operating Range ................................................................................... 41(cid:3)
`Figure 6-1 Accessory Charger Adapter .......................................................................................................... 48(cid:3)
`Figure 6-2 Micro ACA Ports ............................................................................................................................ 49(cid:3)
`Figure 6-3 Micro ACA Architecture ................................................................................................................. 51(cid:3)
`Figure 6-4 Portable Device State Diagram ..................................................................................................... 55(cid:3)
`Figure 6-5 Standard ACA Ports ...................................................................................................................... 57(cid:3)
`Figure 6-6 Standard ACA Architecture ........................................................................................................... 58(cid:3)
`
`
`Tables
`Table 5-1 Voltages .......................................................................................................................................... 43(cid:3)
`Table 5-2 Currents .......................................................................................................................................... 44(cid:3)
`Table 5-3 Resistances .................................................................................................................................... 45(cid:3)
`Table 5-4 Capacitances .................................................................................................................................. 46(cid:3)
`Table 5-5 Times .............................................................................................................................................. 47(cid:3)
`Table 6-1 Micro ACA Connectivity Options ..................................................................................................... 50(cid:3)
`Table 6-2 Micro ACA Modes of Operation ...................................................................................................... 52(cid:3)
`Table 6-3 Standard ACA Connectivity Options ............................................................................................... 58(cid:3)
`Table 6-4 Standard ACA Modes of Operation ................................................................................................ 59(cid:3)
`
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` Battery Charging Specification, Revision 1.2
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`
`
`ACA
`CDP
`DBP
`DCD
`DCP
`FS
`HS
`LS
`OTG
`PC
`PD
`PHY
`PS2
`SDP
`SRP
`TPL
`USB
`USBCV
`USB-IF
`VBUS
`
`
`Acronyms
`
`Accessory Charger Adapter
`Charging Downstream Port
`Dead Battery Provision
`Data Contact Detect
`Dedicated Charging Port
`Full Speed
`High-Speed
`Low-Speed
`On-The-Go
`Personal Computer
`Portable Device
`Physical Layer Interface for High-Speed USB
`Personal System 2
`Standard Downstream Port
`Session Request Protocol
`Targeted Peripheral List
`Universal Serial Bus
`USB Command Verifier
`USB Implementers Forum
`Voltage line of the USB interface
`
`December 7, 2010
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` Battery Charging Specification, Revision 1.2
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`
`1. Introduction
`
`1.1 Scope
`The Battery Charging Working Group is chartered with creating specifications that define limits as well as
`detection, control and reporting mechanisms to permit devices to draw current in excess of the USB 2.0
`specification for charging and/or powering up from dedicated chargers, hosts, hubs and charging
`downstream ports. These mechanisms are backward compatible with USB 2.0 compliant hosts and
`peripherals.
`
`
`1.2 Background
`The USB ports on personal computers are convenient places for Portable Devices (PDs) to draw current for
`charging their batteries. This convenience has led to the creation of USB Chargers that simply expose a
`USB standard-A receptacle. This allows PDs to use the same USB cable to charge from either a PC or from
`a USB Charger.
`
`If a PD is attached to a USB host or hub, then the USB 2.0 specification requires that after connecting, a PD
`must draw less than:
`(cid:120) 2.5 mA average if the bus is suspended
`(cid:120) 100 mA if bus is not suspended and not configured
`(cid:120) 500 mA if bus is not suspended and configured for 500 mA
`
`
`If a PD is attached to a Charging Port, (i.e. CDP, DCP, ACA-Dock or ACA), then it is allowed to draw
`IDEV_CHG without having to be configured or follow the rules of suspend.
`
`In order for a PD to determine how much current it is allowed to draw from an upstream USB port, there
`need to be mechanisms that allow the PD to distinguish between a Standard Downstream Port and a
`Charging Port. This specification defines just such mechanisms.
`
`Since PDs can be attached to USB chargers from various manufacturers, it is important that all provide an
`acceptable user experience. This specification defines the requirements for a compliant USB charger, which
`is referred to in this spec as a USB Charger.
`
`If a PD has a Dead or Weak Battery, then the Connect Timing Engineering Change Notice (ECN) issued by
`the USB-IF on the USB 2.0 spec allows that device to draw up to IUNIT while attached but not connected.
`The conditions associated with this ECN are contained in Section 2 of this specification, and are referred to
`as the Dead Battery Provision (DBP).
`
`1.3 Reference Documents
`The following specifications contain information relevant to the Battery Charging Specification.
`
`
`(cid:120) OTG and Embedded Host Supplement, Revision 2.0
`(cid:120) USB 2.0 Specification
`(cid: