Li-ion Battery Protection ICs for Small Form-Factor Wearables

Nisshinbo Micro Devices has recently unveiled two new 1-cell Li-ion battery protection ICs, the NB7123 and NB7130, specifically engineered for ultra-compact electronic devices like wearables, hearing aids, smartphones, and handheld terminals. These ICs come in WLCSP-8 packages, which are ideal for space-constrained layouts, and offer a host of precision safety features.

For engineers and developers working on battery-powered embedded systems, especially in consumer or medical-grade applications, the level of customization and accuracy provided by these ICs can contribute to safer, more efficient, and longer-lasting battery performance within compact circuit designs.

Safety and efficiency tailored for wearables

Both the NB7123 and NB7130 provide standard protections such as overcharge, over-discharge, overcurrent, and short circuit detection. However, what sets them apart is the precision and configurability of these protection thresholds, which are crucial for devices deeply embedded in the body or worn on the body where battery malfunctions could pose safety risks.

Key features of these ICs include high-accuracy detection of overcharge and over-discharge thresholds, low sense voltage overcurrent protection, 0 V charging inhibition to prevent unsafe charging, and thermal monitoring capabilities through an external sensor connection.

The NB7123 is designed to support high-side MOSFETs, simplifying layout complexity by connecting the control circuitry to battery ground. On the other hand, the NB7130 offers a different architecture with low-side MOSFET control, slightly lower quiescent current, and the same core protections.

Configurable standby modes and low power operation

Both ICs feature a standby control input that allows them to enter a low-power state when charging is not active. In standby mode, the current consumption drops significantly, making them suitable for applications that require long shelf life or infrequent charging cycles.

The NB7123 and NB7130 are currently available in WLCSP-8-ZA2 and WLCSP-8-ZA1 packages, respectively. Designers have the flexibility to configure various parameters, such as hysteresis type, 0 V charging permission, and protection reset behavior, to meet the specific requirements of their applications. Detailed configuration tables and performance curves can be found in the respective datasheets for further guidance.