Four cell lithium-ion protection chip uses 0.25 μA

March 08, 2017 // By Nick Flaherty
SII Semiconductor, part of Seiko Instruments, has developed a 2-to-4 cell lithium-ion battery second protection device with a current consumption of 0.25 μA, one tenth of that of existing products and the lowest in the industry.

The S-8224A/B Series is aimed at protecting Li ion batteries in laptop computers, power tools and other portable devices from overcharge, overdischarge, overcurrent and short circuits.

The use of a secondary protection IC like the S-8224A/B Series is especially critical in cases of overcharge conditions which may result in heating and ignition of the Lithium-Ion batteries. The S-8224A/B provides the design engineer with another robust layer of safety.

The other main features include overcharge detection voltage accuracy of ±20 mV, which provides for further enhanced safety monitoring of lithium-ion batteries  and an SNT-8A package measuring 2.5 x 2.0 x 0.5 mm, which leads to a reduction in the size, thickness and weight of portable devices.

In addition, the output control function paves the way for adding a PTC-based temperature protection function. This allows the S-8224A/B Series to detect not only overcharge, but also abnormal temperatures. Moreover, the device has a gate connection terminal of the charge control FET equipped with an output voltage control circuit, meaning that the series is also compatible with a FET with a gate-source withstand voltage of 12 V.

The datasheet is at