1-cell battery protection ICs for smartphones and wearables

ABLIC, a group company of MinebeaMitsumi Inc., has launched the S-821A/1B Series of 1-cell battery protection ICs, which realize high side protection using N-channel MOSFETs).

1-cell lithium-ion batteries are used in a wide variety of applications, including smartphones, wearable devices, and other IT devices. There has been a growing trend towards the use of higher capacity lithium-ion batteries in recent years as smartphones have become more high performance, and this has in turn resulted in an increase in lithium-ion batteries which use metal casings as they provide more battery capacity per unit volume than conventional insulated battery types. The metal casings serve as negative electrode potential for the batteries, so protection measures are required to isolate the battery’s positive side current path (high side protection) in order to achieve short-circuit protection for the battery’s output terminal. The S-821A/1B battery protection ICs for offer the following features:

N-channel high side protection — Placing an Nch MOSFET which carries out charge-discharge control on the positive side (high side) of a lithium-ion battery makes the ground levels of the battery pack and the system the same, which makes system design simpler. Because the product has a built-in 3 times boost charge pump, the N-channel MOSFET drive voltage can be increased and the N-channel MOSFET on resistance reduced.

High degree of safety through 3 levels of discharge overcurrent protection — The battery protection IC is equipped with 3 levels of discharge overcurrent protection making it possible to isolate abnormal current in safer areas. This achieves industry top-class detection voltage accuracy and improves application device safety.

Industry top-class overcharge detection voltage accuracy of ±15mV — The battery protection ICs achieves an industry top-class overcharge detection voltage accuracy of ±15mV. Improving the accuracy of overcharge detection voltage makes it possible to maintain safety while maximizing battery performance.

A power-saving function which can minimize current consumption — The S-821A/1B Series is equipped with a power-saving signal input pin (PS pin) which allows for the power-saving function to be operated by an external signal which can disable discharge from the battery while reducing the protection IC current consumption to a maximum of 50nA to minimize current consumed by the battery to as close to 0 as possible.

Overheat protection function configuration through connection of an NTC thermistor — An overheat protection function can be configured by connecting an NTC thermistor to the thermistor connection pin (TH pin). Either a 100kΩ or 470kΩ NTC thermistor can be used.

These features provide benefits including strengthening safety countermeasures against battery combustion and other risks, and minimizing loss of remaining capacity during storage in order to greatly contribute to improvement of overall device safety and ease of use.

Going forward, ABLIC will continue to develop lithium-ion battery protection ICs with even greater accuracy and higher performance and to release products for applications in a wide range of fields.

S-821A/1B Series