New Products: 1-cell Li-ion Battery Protection ICs, NB7141 Se-ries, World’s First Product with Built-in Watchdog Timer, and NB7140 Series, Product with Forced Reset Function

These two new products feature industry-leading high-accuracy overcharge, overdischarge, and discharge overcurrent detection functions for 1-cell batteries, as well as a forced standby function. In addition, 0 V battery charging inhibition voltage of the two new ICs is configurable more flexibly than that of conventional ones. Furthermore, the NB7140 series has a forced reset function, and the NB7141 series is the world’s first 1-cell protection IC equipped with a watchdog timer function. They contribute to the competitiveness of customers‘ Li-ion battery applications with high accuracy, low consumption, improved safety, and small dimensions.

Features

1. World’s First Product with Built-in Watchdog Timer (NB7141)

Incorporating a watchdog timer makes it possible to externally monitor a microcontroller in case of uncontrolled operation. This eliminates the need for additional specialized ICs and reduces mounting area. Compared to a watchdog timer embedded in a microcontroller, it can ensure more safety because there is no risk of watchdog timer malfunction due to common causes with the microcontroller.

2. Forced Reset Function (NB7140)

Using the RST (reset) terminal enables to turn off the charge and the discharge FETs, which makes the leak test of the protection circuit easily. Additionally, installing the RST terminal allows the system power supply to be cut off by turning off the FETs when a microcontroller runs out of control, which can reset the power supply to the microcontroller. This improves the stability of the system.

3. Industry-leading High-accuracy Two-step Discharge Overcurrent Detection

Discharge overcurrent detection voltage 1:

0.005 V to 0.030 V, Accuracy: ±1.0 mV,
0.0305 V to 0.050 V, Accuracy: ±1.5 mV

Discharge overcurrent detection voltage 2:

0.011 V to 0.060 V, Accuracy: ±2.0 mV,
0.0605 V to 0.100 V, Accuracy: ±4.0%

The low voltage and higher accuracy of the overcurrent detection allows using a sense resistor with low resistance. This reduces the impedance of a battery pack, thereby reducing the heat generation at high currents and simplifying the thermal design of a board.

4. Industry-leading High-accuracy Overcharge Detection

Detection voltage range: 4.2 V to 4.7 V, Accuracy: ±15 mV. The improved accuracy contributes to strengthening safety in the trend of charging voltage increase.

5. Industry-leading High-accuracy Overdischarge Detection

Detection voltage range: 2.1 V to 3.2 V, Accuracy: ±35 mV. This contributes to longer battery life by enabling the remaining battery charge to be used as close to an allowable value as possible.

6. Industry-leading Low Supply Current

(Normal Mode)

NB7140: Typ. 1.5 μA / Max. 3.0 μA (25% improvement compared to our conventional product),
NB7141: Typ. 2.0 μA / Max. 4.0 μA

(Standby Mode)

Max. 0.04 μA (Overdischarge detection latch type),
Max. 0.20 μA (Overdischarge detection auto release type)

A long operating time of applications is achieved thanks to low supply current at normal mode and standby mode.

7. High-accuracy 0 V Battery Charging Inhibition Voltage

Setting range: 1.0 V to 2.5 V, Accuracy: ±4.0%
Since charging 0 V batteries (low-voltage batteries) may cause an internal short circuit, it can meet the demand for detailed settings of the inhibition voltage from a safety viewpoint. 

8. Forced Standby Function

The STB (standby) terminal makes it possible to enter forced standby mode without putting batteries into overdischarge state, which reduces current consumption significantly until a charger is connected. This makes it possible to minimize battery loss during inventory periods prior to product shipment.

9. Package

An ultra-thin, ultra-small and leadless package WLCSP-8-P10 (1.6 × 1.0 × 0.3 mm) is adopted.

Main Specifications

Availability and Pricing

Fore more information availability and pricing please visit email: sales.europe@macnica.com.

About Nisshinbo Micro Devices Inc.

Nisshinbo Micro Devices Inc. is the result of the integration of former New Japan Radio Co., Ltd. and former RICOH Electronic Devices Co., Ltd. Both companies, having contributed to expanding the Nisshinbo Group’s microdevices business so far, will further grow as an "Analog Solution Provider" for growing markets by strengthening our structure and achieving synergies through business integration.

Nisshinbo Micro Devices will provide analog solutions through electronic devices and microwave products based on the strength of analog technology in accordance with the Nisshinbo Group’s corporate philosophy of "Change and Challenge! For the creation of the future of Earth and People". We will contribute to developing connected society, and aim to be a company with value and presence that is expected by customers around the world.

For more information, go to https://www.nisshinbo-microdevices.co.jp/en/.