The RAJ240090 from Renesas is a Li-ion Battery Fuel Gauge IC that has been designed to support up to 3-8 Li-ion or Li-Polymer battery cells stacked in series. It requires an input voltage of 4-50 V for operation. This fuel gauge IC is built using Renesas’s ultra-low-power RL78 CPU core, enabling multifunctional processing. It combines a microcontroller unit (MCU) and an analog front-end (AFE) within a single package, providing robust and comprehensive battery management capabilities. This battery management IC (BMIC) supports an 18-bit resolution sigma-delta A/D converter that is dedicated to current integration for accurate current flow measurement to support precise state-of-charge (SoC) calculations. It is integrated with an impedance measurement circuit capable of simultaneously measuring battery voltage and current, enhancing overall battery monitoring and management accuracy.   

This BMIC supports a real-time clock (RTC) function to connect to the external crystal resonator and generate an internal clock for synchronization. It incorporates protection features such as short circuit current detection, charge over-current detection, discharge over-current detection, charge wakeup current detection, and discharge wakeup current detection functions. This BMIC is available in a surface-mount package that measures 10 x 10 x 1.7 mm and is ideal for e-bikes, e-scooters, pedal-assist bicycles, power tools, vacuum cleaners, drones, battery backup systems, and energy storage systems (ESS) applications.