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STMicroelectronics introduces breakthrough BMS controller for optimized lithium battery performance

BMS Controller
BMS Controller

STMicroelectronics, the renowned company that designs chips, has recently unveiled a battery management system called the L9961. This device provides accuracy and flexibility to improve the performance, lifetime, and safety of lithium batteries. The L9961 is useful for batteries with a maximum voltage of 25V and is equipped with various features like a dual pre-driver for controlling battery-pack safety relays. it also comes with an embedded non-volatile memory for configuration data, and last but not least, an I2C interface for configuration and host communication.

With an accurate high-resolution analog-to-digital converter (ADC) and current-sense amplifier, the L9961 has an accuracy of ±15mV for cell voltages and 0.25% for battery current sensing. The precise measurements enable high-accuracy passive cell balancing, coulomb counting and various safety features, including overvoltage, undervoltage, overcurrent detection and short-circuit in-discharge protection. The L9961 can also monitor the pack temperature and perform pack-fuse management with over/under-temperature detection when connected to an external thermistor.

The L9961 minimizes energy consumption from the battery pack, while also extending its lifetime and increasing safety. With two power-saving modes, it cuts current consumption down to 2μA in deep-sleep and 5μA in standby. It is available now in a 32-lead 5mm x 5mm x 1mm VFQFPN package, and prices start from $1.19 for orders of 1000 pieces. The L9961 is suitable for battery packs in applications requiring high energy density of lithium batteries, such as backup energy-storage systems, portable and semi-portable equipment, medical devices, and cordless power tools.

Key Features of L9961

  • Extremely low power consumption in sleep mode and standby mode.
  • Has a built-in power supply for controlling the MCU and LEDs.
  • Measures the voltage of up to 5 cells and has over/under voltage protection and balance protection.
  • Has high accuracy voltage measurement and temperature measurement capabilities.
  • Measures battery current with protection against over-current and short circuits.
  • Has an I2C interface for programming and data transfer.
  • Supports up to 70 mA per cell for cell balancing.
  • Provides reliable pack relay management and pack fuse management.
Component Datasheet

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