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Wireless Charging TV Remote Project

Other Parts Discussed in Thread: BQ500212A, BQ51050B, BQ500511, BQ50002, BQ500212, BQ51013B

Hi, 

I am starting on a project where I want to wireless charge a tv remote. 

I would like to know which product (receiver and transmitter) would be the best to work on from scratch? Some of the spec I need is to detect for foreign objects, qi wireless charging, and communication between the receiver and the transmitter to let the transmitter know that the receiver is fully charged.

I have been looking at both BQ51050B and BQ500212A though I have some concerns if these are good for my project. Are they both compatible with each other (I ask because of the letters B and A).

Do program these chips to set up functions? If so, what program should I be using? Sorry I am coming from MSP430 background.

Thanks

  • Gee Won,

    What is the expected charging current for your TV remote?  What is the charging voltage for the solution?

    The bq51050B and bq500212A are completely compatible and make a very good solution.  When the bq51050B reaches charger termination, it sends a "charge complete" signal to the bq500212A which will cease power transmission.  The bq500212A will check to verify that the bq51050B is still on the pad from time to time and the bq51050B will continue to send a charge complete signal.  If the battery voltage drops, it will automatically begin the recharge process.

    For a transmitter, you may consider the bq50002 + bq500511 chip set.  They allow for a smaller solution size.

    There is no programming required to make the devices work together.  If you order the EVMs for each device, they will work right out of the box.  Just remember to hook up a load to the BAT output of the bq51050B to emulate a battery.  This would either be a battery to charge, or typically a source meter to emulate the battery.

    Regards,

    Dick

  • Hi Dick,

    I was wondering what is the advantage using the bq50002 + bq500511 chip set vs. bq500212.
    Wouldn't bq500212 be better since there would be fewer connections and issues compare to two chips?

    If the the reason is the size then I would also like to mention that I want to have the device to charge both TV remote and a smart phone.

    Also I notice that you didn't mention about foreign object detection for the bq500212; though, I did read that there is a setup for one to have is enable. Also for the bq50002 + bq500511

    I would like to avoid the EVM since this project starts from scratch. I may order them to determine the charging rate for current and voltage if you think that is ideal.

    Thanks
  • Gee Won,

    Although the bq50002 + bq500511 starts with two chips, the overall BOM will be roughly 30% smaller.  You can look at bq50002EVM-607 for the details.

    Foreign Object Detection (FOD) is active on both solutions.  It is required by the Qi specification.

    Regards,

    Dick

  • Okay thanks.

    What is needed to increase the distance for charging? I want to implement this design where you can put the charger underneath the table. I assume the distance for the bq50002evm is really small.

    Couple more things. What coil product do you recommend? Also would the shape of the coil impact the performance? I ask since the remote's coil may have a rectangular shape while the transmitter's coil is circular shape.

    Also what socket would you recommend for bq5105brhlr, bq50002rhbr and bq500511rhar? I want to prototype but I require a socket to replace these chips if they are burned. Also the socket is easier to solder. :D

  • Gee Won,

    The charging distance for WPC/Qi products is relatively small (5mm).  Some furniture has the transmitter built into the tabletop - requires a modified design.

    The shape and size of the coils do make a difference in efficiency.  The shielding material also has an impact.  The bq51013B datasheet (table 7) shows some Recommended RX coils.  These have been proven to be very effective in out EVM products.  The same manufacturers do have other coils that may be more suitable to your end solution.

    I do not have a socket recommendation.  I have checked with some of our test team and they have used several companies including Enplas and Plastronics.

    Regards,

    Dick

  • Dick,

    I was wondering if you clarify my purchase. I ordered bq50002evm. I was wonder why it is 30% less components than bq500212evm. I noticed that the bq500212 has a sleep/snooze mode while the bq50002evm does not. This is important function for me to have. Is there a way to implement a sleep/snooze mode to the bq50002evm? Or do should I return it and purchase the bq50002evm?

    Also is there any other functions missing or different between the two?

    Thanks

  • Hello Gee Won
    I can assist with questions on the TX.

    I was wonder why it (bq50002 EVM) is 30% less components than bq500212evm? – The bq50002 and companion chip bq500511 are designed to reduce the number of external components required for a wireless power transmitter solution.
    The bq50002 IC will integrate:
    * Power stage, 4 mosfets + drivers
    * Input current sense amplifier
    * Vin LDO to power the bq500511
    When comparing the 002 / 511 with 212A design you will notice that only external resistors and capacitors are required to complete the design.

    I noticed that the bq500212 has a sleep/snooze mode while the bq50002evm does not. This is important function for me to have. Is there a way to implement a sleep/snooze mode to the bq50002evm? ---To reduce standby (No RX) power on the bq500212A system the main IC is powered off between analog / digital pings using the sleep / snooze function. See FAQ section there is a presentation this function.
    The bq50002 / 511 system standby power is much lower and does not need to be turned off to reduce power.

    Or do should I return it and purchase the bq50002evm? --- Both designs will work.

    Also is there any other functions missing or different between the two? --- From a user standpoint the two will perform the same.
    Also if you are interested in increasing the distance between RX and TX coil the bq500212A will probably work better. Both will meet the WPC / Qi requirement of coil to coil distance of 1.75mm to 5mm. But demodulation circuit of the 212A will work better and should enable a proprietary solution to work better at greater distance. In a proprietary this would be only your TX operating with your RX. Mechanical alignment to put the coils in the best position is recommended.