New series delivers secondary protection ICs for notebook PCs

ABLIC has launched the S-82M3/M4 Series secondary protection ICs for notebook PCs serially connected to cell packs and the S-82L4 Series secondary protection ICs for notebook PCs serially connected to three to four cell packs.

Secondary protection ICs protect lithium-ion batteries from overcharging when combined with a protection fuse which blows when an external signal is received. For notebook PCs and tablet PCs in particular, temperature protection and RTC drive are required, so secondary protection ICs can be equipped with both a function to protect battery packs from abnormal temperatures and a function to output the necessary constant-voltage to RTC drive by connecting an external PTC thermistor.

Both series are secondary protection ICs developed based on customer demand for greater safety and reliability. They are the company's first products, which provide overcharge protection, a CTL pin that allows temperature protection through connection with a PTC thermistor as described above, and a constant-voltage output pin for driving an external RTC, all on a single chip.

For the series, the S-82M3 Series is for serially connected three-cell packs, and the S-82M4 Series is for serially connected four-cell packs. They are equipped with a wake-up function to prevent protection fuses from blowing during battery pack assembly in the manufacturing process. The S-82L4 Series, however, is not fitted with a wake-up function but is compatible with serially connected three-cell and four-cell packs.

The features of these new products include being equipped with a CTL pin, which allows for temperature detection through connection to a PTC thermistor; the ability to supply low power to an external RTC through an included constant-voltage output circuit available at a minimum voltage of 1.5 V; and the series is equipped with a wake-up function which prevents protection fuses from blowing during battery connection. This wake-up function is a function that monitors whether all batteries have been connected and prevents the protection fuse blowing signal from being output until all batteries are connected, no matter what order the batteries and protection circuit board are connected in. This function permits the protection circuit board and batteries to be connected in any order, which contributes to improved work efficiency in the assembly process.