Other Parts Discussed in Thread: BQ76972
Tool/software:
Hi,
We're using the BQ76940 IC as the AFE for our BMS. During operation, abnormal cell voltage readings were observed (0V and 6.0V). This was seen on adjacent cells, and this issue appears usually when cell connectors are attached. On replacing the IC the issue does not appear until we reattach the cell connectors again. This was concluded to be a problem due to Hot Plug because of a Random Cell connect. The datasheet mentions that the IC is random cell connect tolerant, but this issue appears randomly and unpredictably on attaching the cell connector.
The balancing algorithm does not allow adjacent cells to be balanced as well (external FETs used for balancing).
What may be the reason for this and how can we mitigate it? (Apart from connecting VSS first)
We are also using the BQ76972 IC for our upcoming design and we do not want to replicate such an issue again, are there any suggestions to avoid this from happening?
It would be helpful if the Hot Plug random cell connect limitations for this series of ICs could be explained as well.
Thanks!
Akshat Madaan