Wireless Power: The Qi standard and bqtesla TM Solutions

Transcription

1 Wireless Power: The Qi standard and bqtesla TM Solutions

2 Wireless power technologies TI, Philips, Fulton, Convenient Power, Sanyo and more Conductive Charging (Wildcharge, Duracell) Wireless Power Consortium Palm, Powermat RF Wireless Power (Powercast) Toothbrush, Witricity 2

3 Wireless Power Consortium (WPC) Proprietary Solutions Interoperability key to adoption WPC Industry wide standard for delivering wireless power up to 5W Aimed to enable interoperability between various charging pads and portable devices Standard continues to gain traction with increasing list of members (80+) Compatible devices will be marked with a Qi logo Broad Industry Support and more 3

4 Inductive Power System Overview Power AC to DC Drivers Rectification Voltage Conditioning 5V Li Ion Battery Communication Controller V/I Sense Communication and Control Transmitter Receiver Power transmitted through shared magnetic field Transmit coil creates magnetic field Receive coil in proximity converts field into voltage Shielding material on each side directs field Power transferred only when needed Transmitter waits until its field has been perturbed Transmitter sends seek energy and waits for a digital response If response is valid, power transfer begins Power transferred only at level needed Receiver constantly monitors power received and delivered Transmitter adjusts power sent based on receiver feedback If feedback is lost, power transfer stops I D z < D 4

5 System Efficiency Dependencies Good Efficiency when coils less than one diameter apart Coupling between coils Distance (z) between coils Ratio of diameters (D 2 / D) of the two coils Physical orientation Quality factor Ratio of inductance to resistance Geometric mean of two Q factors Uncoupled field has no losses Near field allows TX to see RX Higher efficiency Lower efficiency Optimal operating distance 40% at 1 diameter 1% at 2.5 diameter 0.1% at 4 diameters 0.01% at 6 diameters Efficiency is Optimal when Coils are Less than One Diameter apart 5

6 Transmitter Receiver Load Power Pickup Unit C s Cd L s C Primary coil (Lp) + serial resonance capacitor (Cp) Inverter: e.g. half bridge Controlled by e.g. frequency or voltage Secondary coil (L s ) Serial resonance capacitor (C s ) for efficient power transfer Parallel resonance capacitor (C d ) for detection purposes Rectifier: full bridge (diode, or switched) + capacitor Output switch for (dis-)connecting the load 6

7 Communication - Basics Primary side controller must detect that an object is placed on the charging pad. When a load is placed on the pad, the primary coil effective impedance changes. Analog ping occurs to detect the device. After an object is detected, must validate that it is WPC-compatible receiver device. Digital Ping transmitter sends a longer packet which powers up the RX side controller. RX side controller responds with signal strength indicator packet. TX controller will send multiple digital pings corresponding to each possible primary coil to identify best positioning of the RX device. After object is detected and validated, Power Transfer phase begins. RX will send Control Error Packets to increase or decrease power level WPC Compliant protocol ensures interoperability. V OUT, I OUT Control processor on RX side will apply load pulses for signaling back to TX. Load current is sensed on primary side demodulated to get signaling data. 7

8 Switching Frequency Variation System operates near resonance for improved efficiency. Power control by changing the frequency, moving along the resonance curve. Modulation using the power transfer coils establishes the communications. Feedback is transferred to the primary as error. 80 KHz 100 KHz 120 KHz 8

9 bqtesla Wireless Solutions Gen1 & Gen2 Power AC to DC Drivers Rectification Voltage Conditioning Load Communication Controller TX Solutions bq (Gen2) bq (Gen2) bq (Gen1) V/I Sense Controller RX Solutions bq51013 (Gen2) bq51011 (Gen2) bq25046 (Gen1) MSP430bq1010 (Gen1) Transmitter Receiver 9

10 Efficiency (%) Gen 1* and Gen 2 WPC System Efficiency 80 bqtesla TM - Gen 1 and Gen 2 System Efficiency with 5-V Receiver Gen 2 - BQ51013 Gen Output Power (W) *Gen 1 Rx system built using discrete rectification, LDO for voltage conditioning and Micro for communication control. Gen Rx integrated all three functions into a single IC 10

11 bqtesla EVMs bqtesla Evaluation Modules New bq51013evm

12 Qi-compliant RX coil used w/ EVM kit 40-mm x 30-mm x 0.75-mm WPC Compliant Receiver Coil 12

13 bq51013 form factor demo PCB (PR1041) 5 x 15 mm footprint for all RX side circuitry Represents what an OEM would design into their actual end-product to enable wireless power from a QI-compliant charging pad. 13

14 Gen1 and Gen2 EVM Comparison bq V SWIFT Regulator Gen 1 EVM 3.3V SWIFT Regulator Buzzer Gen 2 EVM Analog Demodulation Power Train CT BOM Count: 160 ~2600mm 2 (50 x 52mm) MSP430 bq Power Train BOM Count: 71 ~1200mm 2 (30 x 40mm) Replaced INA214 to INA199A2 (Shunt monitor) Drop-in replacement Retains high-side sensing Replaced CSD17308 to CSD17313 (Power MOSFET): Smaller and fully released - samples available Added TLV70033 (low power LDO) to remove power to bq in standby mode Reduces Iq to <5mA (w/ LED), or <4mA (no LED) 14

15 PACK- PACK+ bq51013 General 5V Power Supply Integrates synchronous rectification, voltage conditioning, communication control bq51013 acts as a Power Supply to deliver 5V to the VIN pin of the system charger bq51013 automatically selects between AC adapter/usb and wireless input power sources Provides adjustable current limit protection and coil overvoltage protection Host interface can enable OTG mode via EN1 = 1 or charge termination with EN1 = EN2 = 1 USB or AC Adapter Input 5V 5W bq24180 VBUS SW Adapter Detection Adapter Enable 30V rating /AD-EN AD bq51010 OUT Host Control of End Power/ Fault PMID BOOT PGND Receiver Coil Power supply current limit programmable via an external resistor. C5 CBOOT1 BOOT1 C1 AC1 COIL C2 AC2 BOOT2 CBOOT2 COMM1 CCOMM1 COMM2 CCOMM2 ILIM R1 RECT VTSB TS/CTRL /CHG EN1 EN2 PGND C4 C3 R2 NTC R3 Status R4 D1 D+ D- USB PHY PSEL HOST VAUX SCL SDA INT SYSTEM CLMP DCO TS CSIN CSOUT AUXPWR DRV TS Pin for Vhot and Vcold protection. Can be used to signal termination or a fault (CTRL) Host Control of Adapter pin functionality PMID Typical Application Circuit 15

16 bq51013 Gen2 Wireless Power Receiver (RX) WPC Compliant Integrated Wireless Power Receiver Solution with a 5V Regulated Supply - 93% Overall Peak AC-DC Efficiency - Full Synchronous Rectifier - WPC v1.0 Compliant Communication Control - Output Voltage Conditioning - Only IC Required Between RX coil and 5V DC Output Voltage Internal Dynamic Rectifier Control for Improved Load Transient Response Supports 20V Max Input Low-power Dissipative Rectifier Overvoltage Clamp (VOVP = 15V) Thermal Shutdown Single NTC/Control 1.9 x 3mm WCSP or 4.5 x 3.5mm QFN Package Integration reduces total system solution board space and cost - Provides more power to end equipment and reduces heat dissipation - Integration into single devices simplifies design and reduces board space - Allows RX to have interoperability with WPC compliant TX solutions - Output regulation provides quiet output voltage ready for load - Simplifies design and reduces board space and cost. Consistent power delivered to system load to reduced power sags Provides broad range of applications and coils Protects the IC from voltages beyond the maximum rating of the IC Prevents potential damage device and lowers power dissipation Optimal Safety and reduces I/O required to Host Saves board space and offers alternate packaging for manufacturing Targeted for low-power (<5W) end equipment: Cell phones - Digital cameras - Portable media players - Remote/gaming controllers - Bluetooth, Headsets - Other portable devices bq51013evm 16

17 GEN1: TX System Diagram GEN2: TX System Diagram 19Vin TPS54231 Buck Regulator X TPS715A01 Linear Regulator X INA214 Current Sense 3.3VDC 5.5VDC CSD17308 NexFET bq500xxx Wireless Power Controller PWM TPS28225 MOSFET DRIVER CSD17308 NexFET Tank/Coil Assembly NTC Serial COM bq Based Designs Converts Analog Demod circuit to Digital Demod circuit Significant reduction in BOM and Area Simplifies Current Sense circuit no Current Sense Transformer Reduces BOM cost and Area Simplifies Regulator circuit for Drivers Reduces cost X 3x OPA LVC1G3157 Active FILTER Uses Lower Cost Power FETs Uses Lower Cost INA amplifier PMOD performance offers improved Linearity and Sensitivity Optional configuration Use lowest cost MSP430 & TLV70033 to implement Standby Mode for Energy Star 17

18 bq500210: Gen 2 Wireless Power Transmitter Controller - WPC Compliant, 1-Bay Single-Bay Wireless Power Transfer Controller compliant to WPC 1.02 specifications Digital Demodulation reduces system BOM and simplifies solution over the bq Demodulates and Decodes WPC Complaint Receiver Message Packets over same Wireless Link that transfers electrical power PID closed-loop power transfer control via frequency modulation (110kHz-200kHz) Real time efficiency analyzer Improved Parasitic Metal Object Detection (PMOD) from bq Overload and Over-Temperature protection 14 programmed LED indication schemes - Controller standby - Power Transfer - Charge complete - PMOD Warning & Stop - System Fault States 7 x 7mm 48 pin QFN Package (Pb Free, RoHS Compliant) Provides simple, cost effective, low BOM count design implementation Reduces external circuitry used in analog implementations Provides closed loop power control system for various application solutions Delivers comprehensive system-level power transfer management Maximizes power transfer efficiency reduces loss & protection Provides protection from power transfer to metal objects, overheating, and power loss Safe and reliable operation Visual operational status and diagnostics Provides small size and ease of manufacturing solution Transmitter Pad for Contactless Charging with WPC Specification 1.0 Compliance Targeted for low-power (<5W) end equipments: cell phones, digital cameras, portable media players, remote/gaming controllers, Bluetooth headsets and other portable devices LOW POWER OPTION with MSP430-G2001 I Q = 15mA P Q = ~300mW I Q_MSP430 = 5mA P Q_MSP430 = ~95mW EVM/Tool bq EVM

19 TI Wireless Power Forum & Wireless Power Web Page TI E2E Community-Wireless Power External Forum available for entire engineering community Ground Rules Keep the questions technical in nature, good question your peers can benefit from at a later date. One question per-post to make it easer to search. Place P/N in Topic with description of question again to make it easier to search. Do not ask pricing or deliver questions TI Wireless Power Web Page 19

20 For technical specs & tutorials: 20

21 Thank You! 21