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.

BQ51003: Power transfer won't reinitialize after setting EN1 & EN2 low.

Part Number: BQ51003

We are setting EN1 and EN2 high on the BQ51003 to send an EPT packet to the transmitter when our battery charge is complete. However, when we set EN1 and EN2 low again, without removing the device from the transmitter, power transfer will not reinitialize. We have to remove the device from the transmitter and place it back on again to reinitialize power transfer. Is there a message we need to send to the transmitter to reinitialize power transfer if the device never leaves the transmitter? We would like the device to remain topped off if left on the transmitter for extended periods of time. 

  • Hello

    EN1 and EN2 high will send EPT Charge Complete and the TX will turn off.  But TX will need to power the RX up to see if it needs more power, check back with it.  This is a function of the TX not the RX. The time transmitter will check back at some point, I have see times as high as 15 min.  

    If a new RX is placed on the charging pad it will detect the quickly, in about 1.5sec.  But different pings are used.  A short ping is used to detect if the RX is moved a long ping is used to power the RX then it can reply.  

  • That is how I understood this was supposed to work, however, we are not seeing the device go back into charging again after setting EN1 and EN2 low. The device was left on the transmitter for a day with EN1 and EN2 set low and charging was never reinitialized.

    Here is what we are doing (device never leaves the TX during this test)

    1) Place device on TX with EN1 and EN2 low

    2) Devices begins to charge

    3) Set EN1 and EN2 high

    4) Device stops charging

    5) Set EN1 and EN2 low

    6) Device never begins charging again

    Is there a reference design where charge, end charge, and recharge is operating with a BQ51003?

    Thank you!

  • Hello

    We have tested this feature has been tested and does work.  No special application circuit is needed.

    A couple of good transmitters to used for test are the TYLT Vu and TYLT Vu Solo.

    Which transmitter are you using and have you tried others?

  • We have tried a Samsung EP-P3100 and a Choetech T511-S , neither of which will ever reinitialize charging. Makes me think we have done something incorrect.

    We did try a TYLT Vu Solo and it did reinitialize charging. If I remember correctly this TX has your/TI's TX IC in it. Does this mean the BQ51003 RX IC will only work with a TI TX IC? 

    Being that we won't know what type of Qi TX the end user will use, we would like to see this working on more than just the TYLT TX.

    What method do you recommend for setting the EN1 and EN2 inputs? Do they need to be held high or held low all the time? We are currently setting the EN1 and EN2 inputs with the charge status output from our charge controller IC, is this acceptable?

    Thanks!

  • "What method do you recommend for setting the EN1 and EN2 inputs?" --Bill J -EN1 and EN2 input for normal operation pull low or float (internal pull down),  pull high to send EPT.  

    "Do they need to be held high or held low all the time? " -- Bill J - Yes, logic level will set the operating mode

    "We are currently setting the EN1 and EN2 inputs with the charge status output from our charge controller IC, is this acceptable?" -- Bill J -- Yes, but this also depends on the charge controller.  

    "We have tried a Samsung EP-P3100 and a Choetech T511-S" -- Bill J -- I have seen this issue with the Samsung unit.  As you have seen it will not restart charge until the RX has been move.  The Choetech is new but may use same chip set.

  • Isn't it part of the WPC communication protocol for the TX to ping the RX every so often and check if power transfer is being requested? I thought this feature and the ping time was standard.