Heat Dissipation and Charge/Discharge Control Options Equipped

SII Semiconductor Corporation, a subsidiary of Seiko Instruments Inc., has introduced two new 1-cell lithium-ion battery protection IC products.

The S-82A1 series integrates a Sense Pin (VINI) that enables very precise detection of overcurrent conditions using an external sensitivity resistor. The S-82B1 series is equipped with a Control Pin (CTL) that allows users to externally control charging and discharging through control pin signals. Both products are suitable for all applications using 1-cell lithium-ion batteries, including smartphones and wearable devices.

The S-82A1 series enables substantially accurate overcurrent detection with respect to operating temperature range and power supply voltage fluctuations using an external sensitivity resistor. This product also achieves overcurrent detection voltage precision of ±3mV during discharge and charge. This industry-leading precision further enhances the safety and reliability of lithium-ion battery packs.

As charging current increases along with battery capacity, heat generation during charging increases, making thermal management an important design consideration. To minimize heat generation in the current state, an overcurrent sensing resistor with low resistance value is required. The S-82A1 series supports overcurrent sensing resistors with low resistance values, allowing the overcurrent detection voltage to be selected and set at 10mV or less during charging and discharging. This unique feature of the S-82A1 series helps reduce heat generation within the protection circuit.

The S-82B1 series integrates a charge-discharge control pin that enables external control of charging and discharging. For example, by connecting a PTC thermistor to the control pin, users can optionally add a thermal protection function that disables charging and discharging of the battery pack.

Additionally, by using the control pin to disable battery charging and discharging on the production line, power consumption can be reduced to the lowest possible level so that finished products reach consumers. Since this function is possible even when the battery pack is connected, it is also convenient to test the current consumption of finished products through battery pack removal simulation.

Both the S-82A1 and S-82B1 series are available in an ultra-compact SNT-6A package (1.6×1.8×0.5mm).