BQ76972: BQ76972 : BJT Cell balancing and Active Cell Balancing

Hello Fairuz,

I was the one who presented the cell balancing discussion a few months back!

Fairuz Ahmad Naufal said:

You said on the BQ769x2 family, we can increase the efficiency of cell balancing, if we utilize the BJT. Could you give the data to illustrate that statement, please?

I mentioned during the presentation that using a BJT instead of a MOSFET can be used to balance lower-voltage cells, as a lower voltage is needed to turn-on the BJT's. However, I also mentioned that a  BJT can be used in conjunction with a MOSFET in order to enhance the gate-source voltage of the MOSFET so that it can see the full cell voltage across its gate-source. Maybe that's what you are referring to? I do not believe I had an image of that.

If needed, I can share the PDF of the presentation to you .

Fairuz Ahmad Naufal said:

I have a plant to use an active balancing on this IC type. However, after I searched and read your design references, I have not found any active cell balancing designs. My question, is it possible using active balancing on the BQ76972? (let say we will use capacitor to balance each cell). If it is possible, could you attach several references relating with that topic, please?

We currently do not have an active cell balancing IC, all of our devices do passive cell-balancing. Active cell balancing is possible with external components and circuitry, but it would all be discrete. We do not have a reference design showing this.

Best Regards,

Luis Hernandez Salomon

Yes please. Maybe it will help me to understand about this problem.

Thanks!