BCC PCB design - Isloated communication to BCC or isolated CAN?

[Poley]

Hey,

I usually use The MC33771C or similar in a distributed system. I need to make a new board which only has 1 BCC but also has CAN output and other controls so will be using a S32K IC.

Which of these 2 options is the suggested route or does it not matter?

1 - Normal S32K circuitry and SBC for power from an external source. Connects to BCC through TPL and transformer isolation to cover cell isolation

or

2 - S32K is powered by a switching reg DCDC from the cells and the BCC is connected by SPI. CAN output will then be through a islolated CAN trasciever and the SBC enable would be through an opto-isolator. - This would have the highest current draw from the cells

Thanks in advacne! Any thoughts are helpful.

[guoweisun]

Hi 

Q:Which of these 2 options is the suggested route or does it not matter?

[GW]The first one.

[Poley]

Great, thank you!

Does this look ok for the on board TPL? Do I still need the diodes around the transformer? Thank you!

[guoweisun]

Sure,you need these diodes for getting protection.

[Poley]

Great, thank you!

And lastly can I confirm that if I want to use LED's to show that balancing is active (1 LED per cell). So LED is off with no current draw from cell when balancing is off and LED is ON when BCC balancing is on:

Starting from Cell 1 here:

Upto Cell 14 here:

Thank you!

[guoweisun]

You can try this mode.