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Dual Mode Coil Design Consideration

8

Dual Mode Coil Design Consideration

8.1

Shielding

Implementation of a shielding mechanism is recommended as part of receiver device. Shielding provides
protection from possible bi-directional interference between wireless charging system and consumer
electronic device. The interference causes may include coupling interference causing development of heat
due to eddy currents, impact on wireless charging data transfer, and so forth. It is recommended to apply
the shield on all the magnetically active area (between the secondary coil and the electronic device).

8.2

Receiver Detection: Attraction and Alignment

When a PMA Transmitter is in standby phase and a receiver is placed on the charging surface, the
transmitter detects the presence of the receiver by using either passive method with a “Hall Effect Sensor”
or by active method with digital pinging.

In the passive method, the transmitter uses a Hall Effect Sensor to detect the presence of a receiver coil.
It measures the voltage difference between no coil on TX and a full aligned coil on TX. If the difference in
the hall sensor measurements between the two cases is above 200 mV, the power transfer phase will
start as required by PMA. In the active method, it uses a digital pinging method instead. This detection
method uses a periodic short pulse or short burst of pulses applied to the primary coil. By measuring the
resultant interference on the primary coil, the presence of a receiver can be detected.

For both methods, a PMA-compliant receiver coil design shall include materials that can trigger the Hall
Effect Sensor and create enough interference on the digital pinging on the PMA transmitters. The
implementation is vendor specific and may rely on the magnetic material used for alignment aid, the
shielding, or any other material designers select.

The alignment aid ferrite should have no more than 2 mm distance from charged device outer surface.
The recommended shielding ferrite placed on the receiver antenna and the alignment aid fit into the hole
at the center of the shielding ferrite as indicated in

Figure 10

.

Figure 10. Dual Mode Coil Example

8.3

Inductor Value

A PMA-compliant receiver operating frequency is between 232 kHz and 278 kHz. For best efficient PMA
only systems, the recommended coil self-inductance is around 4-µH range and coil self-resistance is
around 300 m

Ω

. The operating frequency for PMA is higher than WPC. Thus, for dual mode solution the

inductance has to be increased to meet WPC requirements. For dual mode applications, a recommended
coil self-inductance is about 7.5 µH and coil self-resistance is around 300 m

Ω

.

In this EVM, the 760308102210 coil from Wurth electronics is used as an example for dual mode solution.
Other coils also can be used such as KNCWZ08C409 from Panasonic and ASC-353583M08-S0 V1.0 from
Amotech. The resonant capacitors are not required for PMA mode only. To support WPC and PMA, tuning
resonant caps according to WPC requirement and with the final configuration of the board is a must. Note
that the coil inductance and the required shielding may vary from application to application depending on
the final configuration of the board.

17

SLUUAX6B – February 2014 – Revised June 2014

Dual Mode (WPC and PMA) Integrated Wireless Receiver Power Supply

Submit Documentation Feedback

Copyright © 2014, Texas Instruments Incorporated

Содержание bq51221EVM-520

Страница 1: ... the development of their end applications Contents 1 Introduction 3 2 Considerations with this EVM 3 3 Modifications 4 4 Recommended Operation Condition 4 5 Equipment and EVM Setup 5 5 1 Schematic 5 5 2 Connector and Test Point Descriptions 6 5 3 Jumpers Switches 6 5 4 Test Point Descriptions 7 5 5 Pin Description of the IC 7 6 Test Procedure 8 6 1 Definition 8 6 2 Recommended Test Equipment 8 6 ...

Страница 2: ...Load 16 10 Dual Mode Coil Example 17 11 bq51221EVM 520 Layout Example 19 12 bq51221EVM 520 Top Assembly 20 13 bq51221EVM 520 Layer 1 20 14 bq51221EVM 520 Layer 2 21 15 bq51221EVM 520 Layer 3 21 16 bq51221EVM 520 Layer 4 22 List of Tables 1 bq51221EVM 520 Electrical Performance Specifications 4 2 Pin Description 7 3 bq51221EVM 520 Rev B Bill of Materials 23 2 Dual Mode WPC and PMA Integrated Wirele...

Страница 3: ...aps between them to control the operation point Each PMA receiver will have a unique PMA RXID transmitted in the RXID message Note that the first build of these EVMs do not have RX ID implemented 2 Considerations with this EVM The bq51221EVM 520 evaluation module PWR520 001 demonstrates the receiver portion of the wireless power system This receiver EVM is a complete receiver side solution that pr...

Страница 4: ...1221EVM 520 Electrical Performance Specifications Parameter Test Condition MIN TYP MAX Unit Vrect Rect voltage range 4 10 V IAD_EN_sink Sink current 1 mA IIN Input current range 1 5 A IOUT Output current range Current limit programming range 1 5 A VOUT REG Programmable Output Voltage 1 POUT 5 W 4 5 8 V Fs Switching Frequency WPC 110 205 kHz PMA 235 275 TJ Junction Temperature 125 C 1 The output vo...

Страница 5: ...RB1 GND GND 0 1µF C18 150 R2 FOD TP5 1 2 3 JP1 110 R4 TP4 ADJ TS GND ILIM FIX RECT 56 2k R1 1 2 J3 1 2 J4 1 2 3 JP2 GND CM_ILIM High Low CM_ILIM GND GND 0 1µF C16 TP3 GND GND 0 1µF C6 OUT GND GND AD_EN Rect 1µF C17 GND GND GND Out ILIM FOD AC1 AC2 Orange D2 DNP Green D1 DNP 1 2 3 4 5 6 7 8 9 10 11 J1 1 2 3 4 5 6 7 8 9 10 J2 GND A2 A1 B2 C2 C1 B1 Q1 CSD75301W1015 500 Ohm R6 5k ohm R5 DNP OUT AD GND...

Страница 6: ...turn J5 TS and Return Connector External connection for temperature sense resistor see the bq51221 data sheet SLUSBS9 for additional information Not populated in this spin 5 3 Jumpers Switches The control jumpers and switches are described in the following paragraphs JP1 ILIM Fix or ADJ Max output current is set by ILIM pin In the FIX position the current is set to a fixed value of R4 In the ADJ p...

Страница 7: ...the IC TP5 FOD Input for rectified power measurement for Foreign Object Detection feature in WPC pin F2 of the IC FOD pin for the bq51221 5 5 Pin Description of the IC Table 2 Pin Description Pin Number WCSP bq5122x A1 A2 A3 A4 A5 A6 PGND B1 B2 B3 AC1 B4 B5 B6 AC2 C1 BOOT1 C2 C3 C4 C5 RECT C6 BOOT2 D1 D2 D3 D4 D5 D6 OUT E1 CLAMP1 E2 AD E3 AD_EN E4 SCL E5 VIREC E6 CLAMP2 F1 COMM1 F2 FOD F3 LPRB_EN ...

Страница 8: ...lowing equipment is needed to complete this test procedure Power Supplies Power Supply 1 PS 1 capable of supplying 19 V at 1 A is required power plug to supply the PMA transmitter An adapter usually included on the PMA TX module Loads A resistive load or electronic load that can be set to 5 Ω 1000 mA 10 Ω 500 mA and 5 kΩ 1 mA power rating should be 5 W Meters Two DC voltmeters and two DC ammeters ...

Страница 9: ...r power supply 19 V Transmitter Verify LED D2 is ON UUT Adjust load current to 1000 mA 50 mA Put the receiver EVM on the Transmitter coil and align them correctly After 5 seconds verify that Transmitter Status LED D5 should be green flashing 1 sec You should hear a beep from the transmitter Transmitter LED D2 still ON Receiver LED D1 is ON UUT Verify that Vout is 4 9 V to 5 1 V Between J3 and J4 U...

Страница 10: ... ON UUT Verify that Vout is 4 9 V to 5 2 V Between J3 and J4 UUT Verify that rectified voltage should be 6 6 V to 8 6 V between TP3 and GND Note a modulation signal is present on this voltage every 250 ms and may cause fluctuation in the reading use lower value or base line 6 4 6 Efficiency Test 1 mA Load Verify that input current to TX is less than 80 mA with input voltage at 19 VDC Turn OFF Tran...

Страница 11: ... with 18 V or with the PMA power adapter Connect the output of RX to a battery charger bq24250EVM 150 to charge a battery Set the VBAT to 3 8 V Set the charger current to 1 2 A Set input current limit from the charger to 1 A Monitor the IOUT and VOUT from the RX after putting the receiver EVM on the transmitter coil and align them correctly Figure 2 shows the VOUT and IOUT from the RX as the batte...

Страница 12: ...o full charge state and connect system load to system output of the charger Then put the receiver EVM on the transmitter coil and align them correctly Provide a load step from no load high impedance to 1000 mA on the system load Monitor on side RX load current rectifier voltage and output voltage as shown in Figure 3 Figure 3 Load Step PMA with VIN_DPM 12 Dual Mode WPC and PMA Integrated Wireless ...

Страница 13: ...ansmitter coil and align them correctly Provide a load step from no load high impedance 1000 mA if using current source load Monitor on side RX Rectifier voltage and output voltage as shown in Figure 4 Figure 4 Load Step WPC 13 SLUUAX6B February 2014 Revised June 2014 Dual Mode WPC and PMA Integrated Wireless Receiver Power Supply Submit Documentation Feedback Copyright 2014 Texas Instruments Inco...

Страница 14: ...he transmitter coil and align them correctly Drive the TS pin high 2 V using external power supply Monitor the TS pin PMA signal If a test fixture is used to see End of Charge WPG and output voltage as shown in Figure 5 Figure 5 TS Control Function 14 Dual Mode WPC and PMA Integrated Wireless Receiver Power Supply SLUUAX6B February 2014 Revised June 2014 Submit Documentation Feedback Copyright 201...

Страница 15: ...ransmitters Figure 6 System Efficiency versus Output Current 7 5 AD Insertion and Removal The plot shown in Figure 7 illustrates the behavior of the bq51221 when the AD is inserted while the EVM is on the transmitter pad There is a 36 ms off time during the transition between wireless power and wired power modes Figure 7 AD Insertion and Removal 15 SLUUAX6B February 2014 Revised June 2014 Dual Mod...

Страница 16: ...The peak temperature of the IC 39 C in WPC and 37 C in PMA is well below the maximum recommended operating condition listed in the data sheet Figure 8 Thermal Image in WPC Transmitter 1000 mA Load Figure 9 Thermal Image in PMA Transmitter 1000 mA Load 16 Dual Mode WPC and PMA Integrated Wireless Receiver Power Supply SLUUAX6B February 2014 Revised June 2014 Submit Documentation Feedback Copyright ...

Страница 17: ...t can trigger the Hall Effect Sensor and create enough interference on the digital pinging on the PMA transmitters The implementation is vendor specific and may rely on the magnetic material used for alignment aid the shielding or any other material designers select The alignment aid ferrite should have no more than 2 mm distance from charged device outer surface The recommended shielding ferrite ...

Страница 18: ...ents The dissipation of heat path is important Adding internal layers increases the thermal performance Multiple vias in the PGND pulls of the IC is recommended to decrease the thermal resistance in the board and allow much easier thermal dissipation through inner layer and power ground layers The via interconnect is important and must be optimized near the power pad of the IC and the GND 2 oz cop...

Страница 19: ...1 µF It is always good practice to place high frequency bypass capacitors next to RECT and OUT of 0 1 μF Figure 11 illustrates an example of a WCSP layout Figure 11 bq51221EVM 520 Layout Example 19 SLUUAX6B February 2014 Revised June 2014 Dual Mode WPC and PMA Integrated Wireless Receiver Power Supply Submit Documentation Feedback Copyright 2014 Texas Instruments Incorporated ...

Страница 20: ...llustrate the bq51221EVM 520 layout views Figure 12 bq51221EVM 520 Top Assembly Figure 13 bq51221EVM 520 Layer 1 20 Dual Mode WPC and PMA Integrated Wireless Receiver Power Supply SLUUAX6B February 2014 Revised June 2014 Submit Documentation Feedback Copyright 2014 Texas Instruments Incorporated ...

Страница 21: ...re 14 bq51221EVM 520 Layer 2 Figure 15 bq51221EVM 520 Layer 3 21 SLUUAX6B February 2014 Revised June 2014 Dual Mode WPC and PMA Integrated Wireless Receiver Power Supply Submit Documentation Feedback Copyright 2014 Texas Instruments Incorporated ...

Страница 22: ...s www ti com Figure 16 bq51221EVM 520 Layer 4 22 Dual Mode WPC and PMA Integrated Wireless Receiver Power Supply SLUUAX6B February 2014 Revised June 2014 Submit Documentation Feedback Copyright 2014 Texas Instruments Incorporated ...

Страница 23: ...12D Murata C21 1 2 2uF CAP CERM 2 2uF 16V 10 X5R 0603 603 GRM188R61C225KE15D Murata C22 0 100pF CAP CERM 100pF 50V 10 X7R 0402 402 CC0402KRX7R9BB101 Yageo America D3 1 Green LED Green SMD 1 6x0 8x0 8mm LTST C190GKT Lite On H1 1 Tape segment Low Static Polyimide Film Cut tape section from 36 1 5 x 2 3 5419 1 1 2 3M yard roll H2 1 Case Modified Polycase LP 11B with 4 screws J 6838A Polycase H3 1 Coi...

Страница 24: ... 1W 0603 603 CRCW060327K0JNEA Vishay Dale SH JP1 SH JP2 2 1x2 Shunt 100mil Gold plated Black Shunt 969102 0000 DA 3M TP TP5 3 White Test Point TH Miniature White Keystone5002 5002 Keystone U1 1 DUAL MODE Qi and PMA INTEGRATED WIRELESS RECEIVER YFP0042AWCG bq51221YFP Texas Instruments POWER SUPPLY YFP0042AWCG D1 0 Green LED Green SMD 1 6x0 8x0 8mm LTST C190GKT Lite On D2 0 Orange LED Orange SMD 1 6...

Страница 25: ...rch 2014 to B Revision Page Added information in the abstract including the bq51021 IC as a device that can be evaluated with this EVM 1 25 SLUUAX6B February 2014 Revised June 2014 Revision History Submit Documentation Feedback Copyright 2014 Texas Instruments Incorporated ...

Страница 26: ...ndling and use of EVMs and if applicable compliance in all respects with such laws and regulations 10 User has sole responsibility to ensure the safety of any activities to be conducted by it and its employees affiliates contractors or designees with respect to handling and using EVMs Further user is responsible to ensure that any interfaces electronic and or mechanical between EVMs and any human ...

Страница 27: ...This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instruction manual may cause harmful interference to radio communications Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at its own expense FCC Interference Statement ...

Страница 28: ...érieur au gain maximal indiqué sont strictement interdits pour l exploitation de l émetteur Mailing Address Texas Instruments Post Office Box 655303 Dallas Texas 75265 Copyright 2014 Texas Instruments Incorporated spacer Important Notice for Users of EVMs Considered Radio Frequency Products in Japan EVMs entering Japan are NOT certified by TI as conforming to Technical Regulations of Radio Law of ...

Страница 29: ...esponsible for compliance with all legal regulatory and safety related requirements concerning its products and any use of TI components in its applications notwithstanding any applications related information or support that may be provided by TI Buyer represents and agrees that it has all the necessary expertise to create and implement safeguards which anticipate dangerous consequences of failur...

Страница 30: ...Mouser Electronics Authorized Distributor Click to View Pricing Inventory Delivery Lifecycle Information Texas Instruments BQ51221EVM 520 ...

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