Safeguarding battery packs with scalable multi-cell monitor IC

The L9963E Li-ion battery monitor IC designed for automotive and energy storage systems, provides a fully redundant voltage measurement path with an ADC swap feature and intelligent self-diagnostics to meet stringent functional safety requirements. This ensures enhanced battery protection and supports limp-home operation in fault conditions. It supervises up to 14 series-connected cells for high-voltage battery packs. Multiple L9963E can communicate over an isolated SPI bus, enabling management of battery stacks up with high-speed, low-EMI data transfer. Companion L9963T transceiver chips can bridge the 4-wire SPI to a 2-wire isolated bus for long-distance, high-reliability communications.

Each cell voltage is measured with 16-bit precision, and an on-chip coulomb counter continuously tracks pack current for state-of-charge calculations. The L9963E supports multiple NTC thermistors for temperature monitoring across the battery stack. It also features passive cell-balancing up to 200mA per cell, with both normal and low-power balance modes to minimize current draw during standby. These capabilities help to maintain uniform cell health and accurate state-of-health estimation.

Built with a redundant measurement architecture ensures that any single-point failure can be detected, supporting the highest level of functional safety in automotive battery management. High noise immunity increases reliability in various electric vehicle environments.