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EMB1499Q: 24 Li-ion cells Active cell balancing with Emb1428q & Emb1499q

Part Number: EMB1499Q
Other Parts Discussed in Thread: EMB1428Q

Is there any bi-directional current DC-DC controller available with TI which can support up to 100V stack voltage?. Existing EMB1499Q can support up to 60V stack voltage?. In our application we are using 24 li-ion cells in series. We would like to implement TI based active cell balancing with 4xSwitch matrix driver (Emb1428q) & 2xDC-DC isolated bi-directional controller(Emb1499q). Please see the attachment is this feasible and scalable?

Active cell balancing concept feasibility architecture.pdf

  • Hi Naga,

    The EMB1499 and EMB1428 are a chipset intended to be used together. The EMB1428 expects some feedback from the EMB1499, so I do not recommend using a separate DC-DC.

    I would recommend breaking it into two 12s "sub modules" that could be on the same PCB, just one floating on top of the other. You could follow the EM1402/TIDA-00817 designs
  • Hi David,

    Thanks for the reply, I do considered 2x12 cells and it looks feasible scalability point of view. Is there any limitation or constraint to connect the transformer primary side of forwad DC DC converter to the same 12-cell stack voltage?

    Best Regards,

    Nagamani

  • Hi Naga,

    Please  message me - I have  a couple  preliminary app notes that may be helpful for you while designing. Off of the top of my head, I think it  should be a fairly simple conversion to balance cells back to  the module. We have a TI reference design that is older, but does use the EMB1499 in the way you are asking (TIDA-00239) 

    Link here: http://www.ti.com/tool/TIDA-00239

    There is also  the EM1402/TIDA-00817 to reference. This is a  more  modern version

  • Hi David,

    Indeed it's helpful. Could you please share the application notes which would be useful for automotive application (electric vehicle)

    Best Regards,

    Nagamani

  • Hi David, I am asking to be sure. A single EMB1499 supports 60V without full isolation. In the 16 cell active balancing reference design, a full isolation solution is provided. I understood from that solution, by using full isolation 60V limit does not apply. Am I right?
  • Hi Mehmet,

    If you  are referring  to the EM1402, the cells are balanced to an external 12V battery.  This battery powers the 12V systems in a  vehicle  (or is an AUX battery if being used for  pure energy storage). Typically the high voltage system and the 12V system are  completely isolated from each other, which is where the isolation  comes into play.

    Unfortunately, the question you asked  is not as simple as it would appear. Technically, you can balance to whatever voltage  you may want as long as the isolation is proper. The challenge will  be designing the magnetics and converter to operate properly.

    Could you  share what you are planning to do? I am always happy to help sanity check. IF you do not want to share  here, you can message or email me directly.  If you are working with NagaMani, they also possess my email  address and we can work this offline.