Li-ion battery monitoring LSI delivers industry-low current consumption

August 20, 2015 // By Paul Buckley
LAPIS Semiconductor, a ROHM Group company, has developed a 10-cell lithium-ion battery monitoring LSI that provides a current consumption of 25 μA (typ.) which is 50% less than conventional products.

The company claims the current consumption of the ML5233 is the lowest in the industry, making it ideal for battery protection systems in cordless vacuum cleaners, electric tools, and other portable equipment.

The ML5233 also features an industry-low 0.1 μA (typ.) current consumption during power down, minimizing the effects on battery capacity - even during long-term
storage - and contributing to more eco-friendly products with virtually no loss of charged battery power.

The device's high overcharge detection accuracy (±15 mV per each cell) increases charging efficiency by 7% compared with conventional products that feature ±50mV accuracy.

High-voltage processes support 4-10 cells in series using a single LSI, ensuring compatibility with electric tools and other equipment in the 14 V to 36 V range.
In addition, the versatile design enables scalability to support a wider range of applications. For example, two LSIs can be combined to support up 20 cells in series and up to 72 V, making them suitable for pedal-assisted bicycles, ride-on carts, and other high voltage applications.

In addition, built-in temperature and short-circuit current detection circuits enable detection of not only over-charge/discharge and overcurrent, but also abnormal
(high) temperatures during discharge along with battery pack short-circuits - all without an MCU which decreases footprint by 20% and reduces the number of external components from four to one, leading to smaller battery protection systems and lighter development load.

The demand for battery-driven cordless vacuum cleaners and electric tools utilizing secondary lithium-ion batteries is increasing worldwide every year due to their greater convenience and ease-of-use. Reducing weight to improve portability and other design factors are also considered important.