Battery isolated communication

All monitored parameters, such as the various voltages, temperatures, and currents, need to be transmitted to a main electronic control unit (ECU), for battery state calculations and housekeeping. However, while the ECU often sits in the low-voltage domain, the cell monitoring units sit in different high-voltage islands that must be kept isolated at all times.

This is particularly the case for high-voltage batteries. As such isolated communication is needed to transmit the monitored cell data reliably and cost-efficiently. For this purpose, Infineon offers two types of unique isolation solutions:

• Iso-UART for wired Battery Management topologies
• Low-power Bluetooth for wireless Battery Management topologies

In the wired BMS topology, Infineon offers isolated-UART transceiver solutions with exceptional robustness against noises for both capacitive and inductive types of isolation. The iso-UART offers a robust high-speed communication link across multiple daisy-chained monitoring devices and supports complex battery topologies and up to 1200V battery packs. For additional robustness, the daisy-chaining realizes a redundant ring, which keeps communication up between all connected ICs in case of a broken link. CRC-protected data frames complement communication robustness.

Another method to isolate the CMBs is to use wireless transceivers. The advantage of the wireless topology is that isolation is fully guaranteed at all times. Infineon offers a set of automotive grades low-power Bluetooth devices supporting BLE-connected mesh and offering superior network availability, communication bandwidth, lowest packet error rate, and out-of-the-box end-to-end black channel ASIL-D connectivity.