STMicroelectronics has launched the L9962, a lithium-battery management IC designed to monitor, balance, and protect battery packs using Li-ion and Li-Po cells. The device supports battery packs containing up to 10 cells connected in series and combines accurate cell-voltage monitoring with a 70 mA balancing current, allowing faster correction of cell-voltage differences while helping improve battery efficiency and service life.
The L9962 is designed for a range of portable and semi-portable applications, including cordless power tools, medical equipment, e-bikes, and electric scooters. It can also be used in backup power systems such as uninterruptible power supplies (UPS). Its low-power architecture helps reduce battery drain when equipment is idle or being transported, with power consumption falling to 5 µA in standby and 2 µA in deep-sleep mode.
The IC continuously checks individual cell voltages through a programmable measurement cycle. If an overvoltage or undervoltage condition is identified, the device can activate appropriate protection and cell-balancing functions. It also performs a plausibility check by comparing the overall battery-stack voltage with the selected number of cells. STMicroelectronics specifies accurate voltage measurement across the device’s entire operating-temperature range.
For battery-current measurement, the L9962 includes a precision current-sense amplifier with Coulomb-counting capability. It can identify excessive charging or discharging currents and provide protection against discharge-related short circuits. Current measurement accuracy is specified at 0.25% over the full temperature range, while a single calibration point can be applied during manufacturing.
Battery temperature is monitored through an external NTC thermistor. The IC uses ratiometric measurement to identify both overtemperature and undertemperature conditions within the battery pack.
The L9962 also incorporates several features that can help reduce the number of external components required. These include battery-fuse management and configurable high-side and low-side pre-drivers for controlling battery-pack relays. An integrated 3.3 V low-dropout regulator (LDO) remains operational during standby and can power external components such as a microcontroller or status LEDs.
Communication with the host system is handled through an I²C interface. This allows designers to configure functions such as voltage-measurement timing and access battery information, including state of charge (SOC) and state of health (SOH).
The L9962 is already in production and is available in a 7 × 7 mm, 48-pin TQFP package.
