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TIDA-00239 evaluation board

Other Parts Discussed in Thread: BQ76PL455A-Q1, TMS570LS0432, EMB1412, EMB1432Q, EMB1428Q, EMB1499Q

Hello,

I would like to use TIDA-00239 evaluation board. I checked the schematic and I found that IC LM3S5R31-IQC (U14 in the board) is obsolete. Does TI have other evaluation boards with monitoring, protection, and active cell balancing features? Also, I need to know whether TI has any evaluation boards with just monitoring and protection of series battery cells? Also, I need to know whether TI has any evaluation boards with just active balancing of series battery cells?

Regards,

  • Nima, hello and good morning. we have received your inquiry are have contacted our Battery Management Business Unit to investigate whether we have another eval board that you may be able to use in place of the TI Design that you initially were evaluating for potential use.
    Best Regards,John FulliloveTI Designs
  • Hi Nima,

    The EM1401EVM showcased in TIDA-00239 is meant as a demonstration of the active balance chipset. As such, the MCU and communications portion of the design is really up to the customer to define. We recognize that the EVM solution is getting dated, and as a result we are working on an updated EVM to showcase the active balance chipset. Besides the MCU, the monitor and protector solutions have also been updated since the release of the EM1401EVM. 

    As a result, the next rev of the board (due later this year) will be based on the bq76PL455A-Q1 16-channel monitor/protector. As the bq76PL455A-Q1 includes isolated differential communications, the MCU and isolated CAN circuits are also removed. The resulting solution will depend on control from a pack-level MCU, and there will be demonstration code provided for the TMS570LS0432.

    If you'd like to have more information before the new EVM is released, please feel free to private message me offline.

  • Hello Stephan,

    In TIDA-00239, active bi-balancing cell balancing, 14 cells voltage measurement, 8 cells temperature measurement, 14 cells fault detection are performed by separate ICs (EMB1412 , EMB1428Q, EMB1432Q, EMB1433Q , EMB1433Q ,etc). I need to measure the voltage and temperature of battery cells, and at the same time, I need to keep the battery cell voltage fully protected. It means that I need measurement and protection in the first stage. In the 2nd stage, I need to process logged data (obtained by the 1st stage) in a processor. Then, I will apply output of processed data (obtained in 2nd stage) to the gate drive for active balancing circuit. It seems that the TIDA-00239 suits my application requirements. You mentioned the MCU and communication portion of the TIDA-00239 design is really up to the customer to define. Is it possible to buy TIDA-00239 evaluation module and remove IC LM3S5R31-IQC (U14 in the board) and replace it by one of TI processor (for example a C2000 processor based on your recommendation)? I need to employ my algorithm to process the data (captured/logged by measurement stage), and then provide gate drive signals for active balancing stage.
    I also studied BQ76PL455A-Q1 which provides active balancing with EMB1428Q/EMB1499Q. It seems that the next revision of the board (based on the bq76PL455A-Q1 16-channel monitor/protector) will work for my application too. Can I use the data captured/gathered by bq76PL455A-Q1, and then process the data in a processor using my developed routine and next apply it to an active balancing portion (with EMB1428Q/EMB1499Q)?
  • Your understanding of the required algorithm is correct. The monitor/protector provides the measurement data that is used by the MCU to determine the actual cell to be balanced, and then to send the required command to the appropriate EMB1428Q/EMB1499Q.

    The EM1401EVM referenced in TIDA-00239 is meant as demonstration of active balancing, and was not really designed to bring out all of the signals to bypass particular portions of the design. The signals could be brought out to an external board, but it would be quite a bit of work to do so.

    FWIW, the next version of the actve balance board (EM1402) will not have a MCU at all, but instead the EMB1428Q will be controlled from GPIO on the bq76PL455A-Q1, which is controlled via it's stacked communication interface. in other words, all the GPIO in the entire stack will be controlled from a single MCU at the pack level. However, in this design, I have also added a header so that a user can directly connect a MCU to the SPI signals if they choose. I think this board will be much easier to use.

    I cannot give you an exact time frame for the release of the EM1402 board, as it is still being validated. I expect it to be released sometime around the end of the year.

  • Hello Stephan,
    To sum up, with EM1401EVM, I can measure voltage of up to 14 cells of battery and temperature of up to 8 cells. I also have up to 14 channels fault detection for batteries. However, I cannot measure current of series battery cells. Also I may be able to bring out signals to connect to an external board. I think that I can handle this part.
    With EM1402, there is no processor. I can bring out measured voltages and temperatures (no current again), and do some process in an external processor. Then, I send the gate signals back to EM1402  for active balancing using EMB1428Q/EMB1499Q. Does EM1402 have fault detection too?

    Please let me know whether I am correct.

    Regards,

  • Yes, the bq76PL455A-Q1 used in the EM1402 provides protector fault feedback. Please refer to the bq76PL455A-Q1 datasheet for more info.

  • Hello Stephen,

    Thanks for response. I had checked the bq76PL455A-Q1 datasheet before. The datasheet says that you have additional ADC on the bq76PL455A-Q1. I meant that you may add one current sensor in the EM1402 board to measure the current of series battery cells.  Do you have such current sensor in the EM1402 to measure current and sent the measured data to these additional ADC in bq76PL455A-Q1 or external TI C2000 processor?

    bq76PL455A-Q1is a monitor and protector IC, and does not have processing portion. It can be used for active balancing with EMB1428Q/EMB1499Q. So, it seems that the external/host processor (for example C2000 one) process the measured data (voltages, temperatures, and maybe current) and provide appropriate signals for active balancing   with EMB1428Q/EMB1499Q. Am I correct?

    Regards,

  • EM1402 only implements what would typically be done at the module level, so only local cell voltage and temperature measurement. There is just a single ADC in the bq76PL455A-Q1. The problem with using the bq76PL455A-Q1 to measure current is that the bq76PL455A-Q1 needs to be referenced to the bottom cell -, which if there is a current sense shunt, is not pack -. If the bq76PL455A-Q1 VSENSE0 and GND are connected to pack - (so there is a current shunt between pack- and cell0-), there will be a potential voltage offset applied to the part, which varies with pack load.

    A current sensor really needs to be isolated, which is doable with a device such as the AMC1200S, whose output could be fed into an AUX input and measured together with all the cell inputs. The problem here might be the bandwidth needed to measure the load current you need. A 14-bit ADC might not be enough.

    Typically, customers will implement a separate current sense solution with a higher bit ADC directly input to the host controller and potentially an external high-bandwidth ADC. A pack voltage sense will also be required.
  • Hi Stephen,

    Is the revised version of the EVM based on the bq76PL455A-Q1 with code for the TMS570LS0432 available yet?

    Jason
  • Hi Jason,

    It is in the final stages of getting released, but still may take some time before it is available to be ordered online.

    Regards,
    Stephen
  • I have 2500 miles on an all-electric Corvette. I'm replacing my lead-acid batteries (22 in series - 300V) and looking to build a BMS for this pack as well as the next one (possibly 12 Tesla modules).

    I was looking at the 76PL455EVM and have several questions that may need clarification:

    1. This is a passive method with very low current dissipation and voltage/cell. It looks like I could modify it's dissipation and voltage/cell capability by scaling my packs' input to those expected by the board and software. Any ideas on this?
    2. The photo of the board only shows eight 75ohm resistors while the schematic shows 16. Does board have components on both sides?
    3. Regarding the GUI and software. I haven't looked at the code, but am planning to hack it to run on a Kindle Fire (Fire OS / Android) through a USB adapter. Anything jump out at you where you say... "good luck on that buddy!"?

    What ideas, recommendations, and advice do you have?

  • Very nice!

    The balance resistors can be changed to get a higher balance current, but as passive balance is directly transferring the energy to heat, you really must limit the balance current to ~300mA max. Any more than that really should use active cell balancing which is much more efficient and therefore can accommodate much higher balance currents.

    Another thing to clarify is that the bq76PL455A-Q1 is designed for lithium-ion chemistries. Don't try to use it for monitoring 12V cells.

    There are balance circuits on both sides of the board.

    The GUI source is not available, but there is example MCU code that you use to start from.

  • I've been looking at the designs using the 76PL455 and don't see where battery chemistry is coming into play. For active balancing with EMS570 as a guide and using 1402EVM (Fig. 5) it looks like EMB1499Q is the issue with higher cell voltage - drawing or dumping the charge to the external 12V battery. Other than voltage and current capacity, where does chemistry become an issue? Couldn't external components address the higher current and voltage?
    Thanks
  • Hi Keith,

    My apologies for not replying sooner... I have been away this week.

    I think there is some confusion. The TIDA-00239 mentioned in the thread title does not have bq76PL455A-Q1, and is based on older, discrete monitor and protector devices.You must be referring to TIDM-TMS570BMS.

    I only mention the cell input voltage because of your stated desired to design a BMS for your existing 12V cells AND new Lithium-ion cells. These will need to be 2 different BMS solutions. The bq76PL455A-Q1 can only tolerate 0-5V cell inputs. There is no way to use this device with a 12V cell.

     

    Regards,

    Stephen

  • And... how about now? ;)

    -Mark

  • Hi Mark,

    If you are referring to the next version of the board, TIDA-00817 is on the TI web site, which describes a 16-channel active cell balancing solution, also known as EM1402. I am working on getting it released as an orderable item.

    Regards,

    Stephen