Renesas Electronics announced a charging control integrated circuit (IC), the R2A20055NS, that achieves safe charging control for single-cell lithium-ion batteries used in portable devices. Lithium-ion batteries have a high energy density and can contribute to equipment miniaturization. At the same time, however, they can generate excessive heat and catch fire if they are overcharged.

For this reason, JEITA (Japan Electronics and Information Technology Industries Association) has formulated guidelines that stipulate that charging rates be reduced when the battery temperature is in specific low-temperatures or high-temperature ranges. In addition, there are increasing needs in this equipment for charging using USB bus power when connected to a personal computer by a USB cable, and for charging within the range of power that can be supplied by a USB bus.

While Renesas has mainly focused on IC products for battery chargers and digital still cameras, the company is now releasing the R2A20055NS device, which targets the full range of portable equipment in response to these market needs. In addition to a full complement of the protection features seen as necessary for portable equipment, including battery overvoltage protection and charging timers, this new IC includes functions that implement the charging profiles stipulated by JEITA, allowing the R2A20055NS IC to implement safe charging control. The IC provides control pins for each block to limit the input current. Current limit options are 100 milliamps (mA), 500 mA, or no limit. Thus it can perform battery charging according to the USB power available.

Not only do the R2A20055NS input pins have high withstand voltage of 25 V, but Renesas has added new overvoltage protection functions to the input pins as well. These can protect application systems from the overshoot that occurs when a power adapter or USB cable is connected.

The IC implements the above functions in a 2.0 mm × 2.5 mm high-thermal dissipation 10-pin HUSON package, and thus can contribute to further miniaturization in portable equipment.

Availability

Samples of the R2A20055NS IC will be available in December 2011. Mass production is scheduled to begin in March 2012 and is expected to reach a combined volume of 300,000 units per month in April 2013. (Availability is subject to change without notice.)