bqTESLA FAQ - Wireless Power Forum - Wireless Power

TI Wireless Power Web Page:

Information on TI Wireless Power Products.
http://www.ti.com/ww/en/analog/wireless_power_solutions/index.shtml

Introduction to WPC:

See "Introduction to the Wireless Power Consortium Standard"
http://focus.ti.com/general/docs/lit/getliterature.tsp?baseLiteratureNumber=slyt401

See "How to Implement a 5W Wireless Power System"
http://www.how2power.com/search/article_open.php?article_id=568&orig=NEWSL

See "Take Charge When Creating a Qi-Compliant Wireless-Power Accessory"
http://electronicdesign.com/article/power/Take-Charge-When-Creating-A-Qi-Compliant-Wireless-Power-Accessory.aspx

bqTESLA Device Related:

Q: What TI devices are in the bqTESLA100lp Kit?

ANS: Gen 1 TX HPA688 which includes the bq500110 and the Gen 1 RX HPA687 which includes the bq25046 and MSP430bq1010.

Q: What TI devices are in the bqTESLA150lp Kit?

ANS: Gen 1 TX HPA688 which includes the bq500110 and the Gen 2 RX HPA725 which includes the bq51013.

Q: What is the WPC Certification number for the TX and RX EVM modules?

ANS:    bq500110EVM-688 TX EVM Module: APX-10-1233        bq500210EVM-689 TX EVM Module: APX-11-0629
            bq51013EVM-725 RX EVM Module: APX-11-0318
            bq25046EVM-687 RX EVM Module: APX-10-1146

Q: Is software required for bqTESLa Kit or EVMs?

ANS: No software is required.

Q: What is transmitter input voltage?

ANS: 19VDC +/- 1V, this is also set by the WPC standard.

Q: What is the system efficiency from the TX input to the RX output voltage?

ANS:    The efficiency of power transfer is dependent on system design. The goal is to achieve greater than 70% efficiency for a
            5W system.  The selection of coils, shielding, electronic components and mechanical design influence the overall system
           efficiency

Q: What is the total cost of implementation for WPC solution – electronics and magnetics included?

ANS: TI only controls pricing of TI ICs and it is best for every customer to conduct their independent cost analysis based on the BOM
provided by TI. Using the TI TX and RX BOM can provide an approximate parts list/count for initial analysis.

Q: Where can I find the TI bqTESLA TX and RX EVM BOMs?

ANS: The EVM BOM is listed in the TX and RX EVM module user guides which can be found on TI website at
http://www.ti.com/litv/pdf/slvu429a and http://www.ti.com/litv/pdf/slvu447

Q: Can we use TI’s solutions and develop custom solutions (like non WPC)

ANS: Yes. TI’s technology can be used to develop non WPC solutions.

Q: Can a customer use a generic micro controller and buy wireless power firmware from TI?

ANS: No. TI will sell ICs with firmware embedded into them.

Q: What coil frequency is the power transferred from the base station to the mobile device?

ANS: 110kHz to 205kHz, this is set in the WPC standard.

Q: What measures are used in TI wireless power solutions for metal object detection?

ANS:     As a safety feature, TI’s GEN 1 TX (bq500110) has metal object detection (MOD) and is described in the data sheet section
            entitled “Metal Object Detection (MOD)”.   Another safeguard to MOD is also monitoring temperature of TX pad. The
             bq500110 can be configured to detect parasitic metal placed in the vicinity of the magnetic field. The bq500110 uses the
             power packet information (as received from the powered device) and measured transmitter input power to calculate parasitic
            losses in the system. When excessive power loss is detected, the device will indicate by turning on an LED and provide a
            twenty second warning, and then will disable its PWM output. If the metal object is removed during this twenty second
             warning time, the normal operation will be restored. After shutdown, the bq500110 will attempt to restart normally after
             approximately five minutes. If the object that caused excessive power dissipation is still present in close proximity to the
             field, the sequence will be repeated. To facilitate parasitic loss function, the bq500110 monitors input voltage and current
             supplied to the coil drive circuit.

WPC Related:

Q: What does Low power mean?

ANS: WPC currently has defined low power as systems that consume less than 5W.

Q: If I use TI’s WPC solutions, does it mean we can use a “qi” logo on the product?

ANS: TI’s WPC solutions will ensure that the design will be electronically complaint to WPC requirements. Each end product needs
to be independently certified by the WPC certification labs before a “qi” logo can be authorized for use on a product

Q: Why should I care about WPC, what if my customer wanted to develop a custom solution?

ANS: WPC is developing an industry standard for wireless power transfer. This will allow interoperability among various Tx and Rx
devices following the same standard. The same underlying technology can be used for proprietary solutions

Q: Do I need to become a WPC member to get access to WPC Spec and Qi Logo?

ANS: WPC spec is public and can be accessed at the below link. The Qi logo is only available for members

Q: Where can I find a copy of the Wireless Power Consortium (WPC) Standard?

ANS: www.wirelesspowerconsortium.com/blog/11/qi-specification-available-for-download

Magnetics Related:

Q: Will TI supply magnetics?

ANS: TI will not supply the magnetics. TI will only provide guidelines and a sample as part of the evaluation kit.

Q: Who provides magnetics support during design/development?

ANS: TI will provide recommendations for coils and vendors for both on the Tx and Rx. However, the customer is welcome to
use any magnetic supplier of their choice.

Q: Can I develop magnetics on our own?

ANS: Yes, one can develop magnetics on their own of select a supplier of their choice.

Q: Can I change the TX coil geometry?

ANS: No, the TX coil is defined in the WPC specifications and has no flexibility. This is done to provide maximum flexibility
to the the RX coil design and interoperability.

Q: Who are the magnetics vendors?

ANS: See Below

RX Coil	P/N IWAS-4832FF-50, Vishay Inductor Division, Dir Marketing Tim Shafer, Office: 605-668-4121 www.vishay.com
RX Coil	P/N 760308201, Wurth Elektronik, www.we-online.com
TX Coil	P/N EC00296A, Elytone Electronics Co., Ltd.: Sales Exec Annie Jya, Tel (Taiwan) : +886-2-2671-2071 Ext 301 Cell : +886-972-190- 990, Fax : +886-2-2672-3775 www.elytone.com.tw
TX Coil	P/N Y31-60014F, E&E Magnetic Products, Ltd., Sales 852-29543333 (Hong Kong), www.eleceltek.com, US Sales Contact, Darren Simmons 408-727-4223, Cell 707-363-2448, darren_a_simmon@eleceltek.com
TX Coil	P/N 760308101, Wurth Elektronik, www.we-online.com
TX Coil	P/N X1387-TOKO, www.tokoam.com, US Sales Contact Bob Nau, 619-292-3890, cell 619-392-3645, bnau@tokoam.com

Q: Can the TX and RX coils differ in size?

ANS:      Different size coils can be considered but there will be a coupling and efficiency tradeoffs – please refer to the WPC
             discussion at:
              http://www.wirelesspowerconsortium.com/technology/basic-principle-of-inductive-power-transmission.html

Q: What affects are associated when considering different coil sizes?

ANS: Please refer to the WPC discussions at:
http://www.wirelesspowerconsortium.com/technology/basic-principle-of-inductive-power-transmission.html

and

http://www.wirelesspowerconsortium.com/technology/transfer-efficiency.html

bq500210 EVM Related:

Q: Is the MSP430G2001 needed?

ANS: No, for lowest cost it can be omitted, please refer to the application schematic in the BQ500210 datasheet.

Q: What is the MSP430G2001 actually doing?

ANS: The MSP430G2001 provides additional memory and logic required in more advanced applications.

Q: Do I need to program the MSP430G2001 firmware?

ANS: No, the firmware for the MSP430G2001 is already embedded in the BQ500210 part. At first power up, the BQ500210 performs a 'field update' and automatically boot loads the require firmware to the MSP430G2001. The BQ500210 and the MSP430G2001 then operate in tandem. The automatic firmware boot allows an off-the-shelf blank MSP430G2001 to be used.

Q: How does the BQ500210 know an MSP430G2001 is present?

ANS: A pull-up on pin 25 (MSP_MOSI/LPWR_EN) of the BQ500210 indicates MSP430 is present.

Q: Will a different MCU work instead of an MSP430?

ANS: No, the automatic firmware boot will not work with other MCU's.

Q: Can TI provide the MSP430G2001 firmware for customization?

ANS: No, since the MSP430G2001 firmware is embedded in the BQ500210 it cannot be customized.

Non-TI Development Tools Related:

Q: What non-TI development tools are available?

ANS: Avid Technologies Inc offers both a USB device that can be used to capture the wireless communication packets and other system operating information along with receiver simulator which is used to test the transmitter's operation and performance. See details on Avid Technologies web page: http://www.avid-tech.com/wirelesspower/index.php

Q: Where can I find tool for WPC 1.1 FOD calibration of the TX and RX?

ANS: For WPC 1.1 both the TX and RX will require calibration to indentify internal losses for the customer’s specific application. Unique tool are required to make the measurements and Avid can provide a full suite of devices. Contact Avid Technologies. http://www.avid-tech.com/wirelesspower/index.php