• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 2 answers
  • Subscribers 63 subscribers
  • Views 586 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ51013B: Example layout VQFN package

John Wilson4
Prodigy 30 points
Part Number: BQ51013B
Other Parts Discussed in Thread: BQ51013A, TIDA-00318, BQ51003, PMP11311, TIDA-00668

I am very new to wireless charging design and need help with a few things.  If I can get this running it will potentially mean millions in revenue for TI.

  1. The BQ51013B datasheet has a reference layout for the BGA model but I need to use the VQFN model.  Where can I find an example layout?
  2. I need an example RX circuit that will work with a 1" round coil and a standard qi pad like one of these:

  • 0
    Prodigy 30 points

    I should mention that the case thickness, and therefore coil separation should be 2-3mm

  • 0 in reply to John Wilson4
    TI__Guru* 76056 points

    Hello

    We have not released an EVM or reference design for the BQ51013B with QFN package. 

    But from a layout standpoint the BQ51013A and BQ51013B are the same.  We did release a QFN EVM for the A version, see below link:

    http://www.ti.com/lit/ug/sluu911a/sluu911a.pdf

    Coil that is 1" round -- See TIDA-00318, this uses the TDK WR222230-26M8-G.

    Note small coils work best for lower power, less than 500mA for 1A the larger EVM coil would work best.

    Thickness -- 2-3mm if this is coil to coil distance it is good.

  • 0 in reply to Bill Johns
    Prodigy 30 points

    These are both very helpful, thank you. 

    Since you clearly know your stuff, maybe I should start a bit further back...  I am building an environmental sensor based on the ESP32 microcontroller running at 3.3VDC.  I've been using AP2112-3.3 for the LDO and MCP73831T-2ACI/OT for charging from USB so far but can do something different.  I intend to seal the package completely (potted) so it's impervious to moisture and power it with the following 400Mah battery pack.  I am designing everything myself, including the case, and can do anything required to make this work.  I would like to keep the case dimensions in the 30mm x 45mm range ideally, but can go slightly larger if necessary.  Please answer the following questions:

    1. Is the BQ51013B the best choice to keep this battery charged wirelessly?
    2. I need to stay away from BGA as I am building these by hand in prototyping.  Even QFN is difficult, but it's easier to repair them than BGA if there is a solder bridge caused by my low-tech dispensing solution.
    3. What is the best coil given the battery choice and case size goals?
    4. What is the optimum case thickness or range for this coil, assuming that would mount it to the inside of the case?
    5. Can you point me at a full circuit design that includes component values so I can implement quickly?
    6. I will likely add USB power as a backup while developing and for programming so dual-rail would be helpful - the BQ51013B reference has a circuit design that covers that but has no part numbers for the FETs.

    Thanks in advance - I know I'm asking for a lot, but I don't have much experience in this area and would like to get started on the right foot.  And I need something forgiving...

     

  • 0 in reply to John Wilson4
    TI__Guru* 76056 points

    Hello

    Reply to above question:

    1. Is the BQ51013B the best choice to keep this battery charged wirelessly?--Bill J - It is a good device.  The BQ51003 is better for output current less than 500mA
    2. I need to stay away from BGA as I am building these by hand in prototyping.  Even QFN is difficult, but it's easier to repair them than BGA if there is a solder bridge caused by my low-tech dispensing solution.---Bill J -- This would rule out BQ51003 (BGA Only)
    3. What is the best coil given the battery choice and case size goals? -- Bill J -- use as large a coil as possible, start with coil from EVM.
    4. What is the optimum case thickness or range for this coil, assuming that would mount it to the inside of the case?--Bill J - Coil to Coil distance of 5mm is max.  Try to keep the RX case thickness to about 1mm.  Larger coil and current less than 500mA will help.
    5. Can you point me at a full circuit design that includes component values so I can implement quickly?---Bill J - We have more reference designs for BQ51003, but they can be adapted for BQ51013B. Take a look at TIDA-00318, TIDA-00668, and PMP11311
    6. I will likely add USB power as a backup while developing and for programming so dual-rail would be helpful - the BQ51013B reference has a circuit design that covers that but has no part numbers for the FETs. -- Bill J -- This is a P-Type dual MOSFET, the EVM uses CSD75205W1015 -- 20V 1.2A 190 m ohm, but it is chip scale.  Similar device would work.