New Release of the NB7123 Series and NB7130 Series, 1-Cell Li-ion Battery Protection ICs for High-Side and Low-Side FETs, Respectively

- Contribute to Further Safety Improvements Thanks to Industry-Leading Ultra-High Overcharge Detection Accuracy -

Nisshinbo Micro Devices, Inc. has released the NB7123 and NB7130 series of 1-cell Li-ion battery protection ICs for high-side and low-side FETs, respectively. Both ICs offer industry-leading^*1 ultra-high overcharge detection accuracy of ±6.5 mV.

• *1Based on Nisshinbo Micro Devices Inc. research, as of June 30, 2025.

The market for wearable and hearable devices powered by 1-cell Li-ion batteries is expanding due to factors such as the increasing popularity of virtual reality (VR) and augmented reality (AR). Because they are used especially in devices that are worn directly by humans, safety measures for protective functions, such as preventing battery ignition, are becoming increasingly important. Achieving higher accuracy in the voltages for protect functions is also required.
Meanwhile, the conventional circuit for protecting a 1-cell Li-ion battery mainly uses FETs configured on the low side. However, in recent years, due to the variety of battery cells and the ease of communicating with the host, a growing number of applications have adopted a protection circuit with high-side FETs.
In order to meet market demand, our company has released two types of protection ICs: one for high-side FETs and one for low-side FETs. These ICs provide improved safety by detecting overcharges with ultra-high accuracy. These additions expand our product lineup, making it accessible to a wider range of customers.
In addition to overcharge detection, these products also offer industry-leading accuracy in over-discharge detection, discharge overcurrent detection, charge overcurrent detection, load short circuit detection, 0 V battery charging inhibition voltage, and overtemperature detection. These features contribute to the construction of protection circuits that can further improve safety.
Furthermore, the operating temperature range is from -40°C to 105°C, whereas the conventional product’s range is from -40°C to 85°C. This ensures proper protective operation in environments with higher temperatures.

Features

1. Overcharge Detection Voltage with Industry-Leading Ultra-High Accuracy

• Cell Detection Voltage Range:
  4.3 V to 4.7 V (NB7123 Series)
  

  4.3 V to 4.8 V (NB7130 Series)

  4.3 V to 4.8 V (NB7130 Series)

• Accuracy at 25°C: ±6.5 mV
• Accuracy over -20°C to 60°C: ±8 mV

In the trend of increasing charging voltages, improved accuracy contributes to enhanced safety.

2. Industry-Leading Highly Accurate Charge and Discharge Overcurrent and Short Circuit Detection.

• NB7123 Series
  
  • Discharge Overcurrent Detection Voltage Range:
    0.006 V to 0.040 V, Accuracy: ±1.0 mV
  • Charge Overcurrent Detection Voltage Range:
    -0.006 V to -0.050 V, Accuracy: ±1.0 mV
  • Short Circuit Detection Voltage Range:
    0.020 V to 0.100 V, Accuracy: ±1.0 mV
• NB7130 Series
  
  • Discharge Overcurrent Detection Voltage Range:
    0.006 V to 0.050 V, Accuracy: ±0.75 mV
  • Charge Overcurrent Detection Voltage Range:
    -0.006 V to -0.050 V, Accuracy: ±0.75 mV
  • Short Circuit Detection Voltage Range:
    0.020 V to 0.080 V, Accuracy: ±1.0 mV
    

    0.081 V to 0.125 V, Accuracy: ±2.0 mV

    0.081 V to 0.125 V, Accuracy: ±2.0 mV

Lowering the overcurrent detection voltage with higher accuracy allows for a lower resistance in the sense resistor (R_SENS). Reducing board heat generation and battery pack impedance decreases heat generation at high currents, simplifying board thermal design.

3. Highly Accurate Over-Discharge Detection Voltage

• Cell Detection Voltage Range:
  2.0 V to 3.0 V, Accuracy: ±17 mV

The high accuracy helps extend battery life by using the remaining charge close to the lower limit.

4. Highly Accurate 0 V Battery Charging Inhibition Voltage

• Setting Range:
  1.20 V to 2.00 V, Accuracy: ±20 mV

Since charging 0 V (low voltage) batteries can cause an internal short circuit, the products are designed to achieve high inhibition voltage accuracy from a safety standpoint.

5. Highly Accurate Overtemperature Detection

• Setting Temperature Range:
  40°C to 85°C, Accuracy: ±2°C

Combining the products with an external thermistor enables highly accurate temperature detection. This improves safety by accurately protecting battery packs from abnormal temperatures.

6. Wide Temperature Range

• Operating Temperature Range:
  -40°C to 105°C

Extending the maximum operating temperature from 85°C to 105°C enables the products to function properly in environments where they are exposed to high temperatures, such as industrial equipment applications.

7. Ultra-Small Package

Ultra-small, thin WLCSP packages are adopted.

• NB7123: WLCSP-8-ZA2 (1.66 × 1.08 × 0.38 mm)
• NB7130: WLCSP-8-ZA1 (1.65 × 0.97 × 0.40 mm)

• 

  NB7123

• 

  NB7130

Main Specification (Please refer to the datasheet for details.)

Please refer to the datasheet for details.

Applications

• Li-ion battery pack (1-cell)

Example End Products

• smartphones, tablet PCs, smartwatches, wireless earphones, smart glasses

Typical Application Circuits

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