Nisshinbo Launches Precision Battery Protection ICs for Compact Li-ion Designs

Nisshinbo Micro Devices has released two new battery protection ICs aimed at designers building compact, high-efficiency Li-ion power systems. The NB7123 and NB7130 series target 1-cell applications, with a focus on delivering tighter protection thresholds, flexible system compatibility, and better thermal performance in confined spaces.

The NB7123 supports high-side FET configurations, while the NB7130 is built for low-side. Both offer ±6.5 mV overcharge detection accuracy, a spec that sits among the tightest in the market. That’s particularly useful in devices like wireless earphones, AR glasses, or wearables, where pack space is limited and thermal headroom is minimal.

These devices help engineers push closer to a battery’s rated limits without sacrificing protection, especially as charge voltages continue to rise.

Protection Beyond Overcharge

In addition to overcharge monitoring, both series provide accurate protection against over-discharge, overcurrent, short circuits, and overheating. The overcurrent thresholds are precise enough that designers can safely use lower-value sense resistors. That reduces power loss and board heat, making thermal layout easier in dense assemblies.

For example, the NB7130 can detect discharge overcurrent events with ±0.75 mV accuracy and supports two short-circuit threshold ranges. The NB7123 offers slightly looser tolerances but adds flexibility for high-side switching designs.

Power Efficiency and Temperature Resilience

Both ICs operate across a 1.5 V to 5.0 V input range. Power draw is minimal, 7 µA typical for the NB7123 and 3 µA for the NB7130. Standby current is under 40 nA. They also support an extended operating temperature range of –40°C to 105°C, which broadens their use in environments with limited airflow or nearby heat-generating components.

Thermal protection is handled via an external thermistor, with ±2°C detection accuracy. This allows systems to safely disable charging or discharging in the event of abnormal temperature rise. Added Safety with 0 V Charging Inhibition

When a Li-ion cell falls below a certain threshold, recharging it can trigger an internal short. To prevent this, both ICs include accurate 0 V charging inhibition, with thresholds configurable between 1.2 V and 2.0 V. This helps developers avoid dangerous recovery conditions, particularly in deeply discharged packs.

Compact Packages and Production Scale

Each device is offered in a wafer-level chip-scale package under 1.1 mm wide. The NB7130 measures 1.65 mm by 0.97 mm, while the NB7123 comes in at 1.66 mm by 1.08 mm. This compact form factor makes it easy to place the IC close to the cell, minimising trace resistance and helping with thermal performance.

Both series are now sampling. Production volumes are expected to reach 5 to 10 million units per month, depending on series selection.

Ideal for Space-Constrained Devices

These ICs are designed to meet the demands of modern 1-cell battery applications, including:

• Smartwatches and hearables
• AR/VR hardware
• Portable accessories
• Compact tablets
• Consumer electronics with limited board space

Learn more and read the original announcement here.