Bluetooth and USB Design Considerations

farmer

Contents
1  Introduction.................................................................................................................................................... 4
2  USB Basics..................................................................................................................................................... 5
2.1  Architecture ............................................................................................................................................. 5
2.2  Power Distribution and Suspend Modes.................................................................................................. 5
2.2.1  Low-power Bus-powered BlueCore Device.................................................................................. 7
2.2.2  High-power Bus-powered BlueCore Device................................................................................. 9
2.2.3  Self-powered BlueCore Device .................................................................................................. 11
2.3  USB Enumeration.................................................................................................................................. 14
2.4  Internal Modules, Certification and Non-Spec Compliant Operation...................................................... 17
2.4.1  USB VBUS Monitoring ............................................................................................................... 17
2.4.2  Suspend Mode Current Draw..................................................................................................... 18
2.4.3  PIO Status in Suspend Mode..................................................................................................... 18
2.4.4  Resume, Detach and Wake PIOs .............................................................................................. 19
3  Electrical Design Guidelines....................................................................................................................... 21
3.1  Power Supply ........................................................................................................................................ 21
3.2  D+ and D- .............................................................................................................................................. 21
3.3  PCB Tracks ........................................................................................................................................... 21
3.4  Ferrite Beads ......................................................................................................................................... 21
4  USB Suspend and Bluetooth Low Power Modes ...................................................................................... 23
4.1  Global Suspend..................................................................................................................................... 24
4.2  Selective Suspend................................................................................................................................. 24
4.3  Selective Suspend with Remote Wake.................................................................................................. 25
4.4  Wake on Bluetooth ................................................................................................................................ 26
4.4.1  Permitted Devices...................................................................................................................... 26
4.4.2  Setup Prior to Selective Suspend............................................................................................... 27
4.4.3  Summary.................................................................................................................................... 27
5  Battery Charging from USB ........................................................................................................................ 28
5.1.1  Dead Battery Provision .............................................................................................................. 28
5.1.2  Charge Currents......................................................................................................................... 28
5.1.3  Charging in Suspend.................................................................................................................. 28
5.1.4  USB VBUS Voltage Consideration............................................................................................. 28
6  USB Termination When Interface not in Use ............................................................................................. 29
Appendix A  USB Persistent Store Keys ..................................................................................................... 30
Terms and Definitions ........................................................................................................................................ 34
Document References ........................................................................................................................................ 34
Document History ............................................................................................................................................... 34
【文件名】:11620@52RD_BTand USB_CS-101412-ANP3.pdf
【格　式】:pdf
【大　小】:921K
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