Is it possible to use multiple L9963E with daisy chain without L9963T?

[berg0v1c]

I'm using a single L9963E and it works fine. However, I couldn't start daisy chain connection. When I consider BMS architectures in datasheet, all of them has L9963T transceiver to communicate with further IC. My custom PCB doesn't provide L9963T.

So I have two question:

1- Do I really need a transceiver for USE MULTİPLE l9963E slaves ?

2- Can I use the transceiver on EVAL-L9963E-MCU for this purpoeses?

Bear in mind, I'm using an external MCU, not built in SPC MCU chip.

As I said, I can succesfully communicate single IC and I'm using a cable that has low capacitance.

doesn't

Lastly, according to datasheet the first node of chain can be one of these:
"The daisy chain and dual access ring topologies are based on a chain of BMS evaluation boards. The chain first node can be an AEK-POW-BMSWTX, an AEK-POW-BMSNOTX or an AEK-POW-BMSWTX. The remaining nodes must be all AEK-POW-BMS63EN evaluation boards."

As far as I understand also "AEK-POW-BMSNOTX" does not contain L9963T and it can be use for the first chain of daisy chain. Thus my 4 wire SPI implementation can also be first chain of the daisy chain line. The datasheet is not very clear.

[Peter BENSCH · Accepted solution]

Welcome @berg0v1c, to the community!

1. the transceiver L9963T is required if you need an isolated SPI bus to the controlling mcu
2. the EVAL-L9963E-MCU already contains two L9963T, which can also support a dual access ring

Correct,  the AEK-POW-BMSNOTX does not contain an L9963T, but can still be used for a chain of L9963E - only the SPI bus is not isolated. The battery packs above level 1 are then isolated without L9963T via transformers directly between the L9963E of the previous level and the next higher level (see schematics of the AEK-POW-BMS63EN).

Hope that answers your questions?

Regards
/Peter

[berg0v1c]

Thanks peter, in schematics and examples based on L9963T transceiver. In my case, I have just the L9963E as first node of my system and I can not communicate with second IC. What is the limit of daisy chaining multiple L9963E without transceiver ? 

[Peter BENSCH]

Once again: the transceiver L9963T is only for isolating the controlling MCU from the first level of the BMS if required, NOT for isolating between the levels.

Up to 31 L9963E levels can be arranged in a daisy chain, i.e. max 14x31 cells, which corresponds to a voltage of 1996.4V at max 4.6V per cell.

Regards
/Peter