STMicroelectronics L9963 battery-management system controller for EVs

Click2Contact

STMicroelectronics has announced an advanced battery-management system (BMS) controller designed to increase safety and driving range in electric vehicles (EVs), featuring extra temperature-monitoring inputs for enhanced safety as well as good voltage accuracy for long driving range and battery life.

The L9963 controller is the latest generation from ST’s BMS program. A typical BMS application uses multiple L9963 devices to monitor groups of cells in the battery stack, managed by a host microcontroller (MCU) such as ST’s SPC5 automotive-qualified MCUs.

The product can monitor up to 14 stacked battery cells, measuring voltages with accuracy better than 2 mV in the 1.7–4.7 V range to maintain good cell condition. Simultaneous digitisation of all sensed values eliminates cell-synchronisation delays. The device can also monitor up to seven external temperature sensors, enhancing the system’s ability to detect fluctuations and maintain stability.

Meeting ASIL-D requirements in compliance with the ISO 26262 standard, the product integrates a fully redundant cell-measurement path that enhances safety and provides support for a ‘limp home’ mode. Comprehensive fault-detection and notification functions meeting automotive safety requirements are also built in.

Together with a serial peripheral interface (SPI), the product features a 2.66 Mbps vertical communication interface for high-speed communication between multiple L9963 ICs monitoring the entire battery stack. This permits eight devices to convert and read 96 cells in less than 4 ms, and can work with any combination of transformer-based or capacitive isolation. It also features a robust design that allows hot plugging without the external Zener diodes usually needed to protect the BMS because the battery cannot be powered down.

For more information: www.st.com/automotive-bms.