Passive Cell Balancing Impact On Injection Levels During Direct Power injection on Battery Cell Controller

When it comes to the electromagnetic interference (EMI) immunity of a Battery Management Systems (BMS) or more specifically Battery Cell Controllers Integrated Circuit (BCC IC), Printed Circuit Board (PCB) traces and external components (ECs) arrangement are crucial. The impedance presented by the BCC IC is also a key factor. In fact, such impedance is greatly altered by the cell balancing function of the BCC IC. More specifically, the integrated passive cell balancing function in most commercially available BCC ICs greatly reduces the impedance presented by the BCC IC. This work aims at investigating the impact of different passive cell balancing approaches on the immunity level of the BCC IC. Then a new BCC IC architecture is presented that not only reduces the number of ECs but also allows the passive cell balancing to have the most impact on the immunity of IC, i.e. the injections levels during DPI tests. Thus, the IC can maintain a high voltage measurement accuracy in noisy environments.