Battery charger IC charges low-voltage rechargeable batteries

ROHM developed a battery charger IC – BD71631QWZ – intended to offer low-voltage charging of wearables such as wireless earbuds and thin, compact IoT devices such as smart displays powered by rechargeable batteries.

In recent years the requirement for safer, higher density rechargeable batteries has been directed to new battery types. This comprises all-solid/semi-solid types models utilising novel materials for the electrode part and batteries that adopt different terminal compositions. Yet, many of the latest rechargeable batteries are small and thin, needing low voltage charging in the 2V to 3V range. Furthermore, there are currently no battery charger ICs that are able to handle a wide voltage range.

With this market demand, the company has developed a battery charger IC that supports low voltage charging of not just li-ion but also new kinds of rechargeable batteries such as an all-solid and semi-solid state. The new device delivers low voltage charging over a wide range from 2V to 4.7V by enhancing the stability of the internal circuit.

Unlike general battery charger ICs that offer a fixed voltage, this new device enables the charge voltage to be readily set simply by altering the external resistor, decreasing design load when changing batteries. Also, the original package technology results in a compact package of only 0.4mm thickness, which is 60% lower than conventional products in the market. This contributes to smaller, thinner devices. Furthermore, each charging characteristic like charge/termination current can be set for CCCV charging, presenting an optimal charging environment for thin, compact IoT and wearable devices employing the latest rechargeable batteries.