Machine learning boosts coin cell battery life by 10x ...

Mar 07, 2024

The NBM5100 and NBM7100 use dual DC-DC converters with a storage element and an intelligent learning algorithm. This also increases the peak output current capability by up to 25x compared to a typical coin cell.

This extension in working life will significantly reduce the amount of battery waste in low-power Internet of Things (IoT) and other portable applications while making coin cells a viable power source for applications which could previously only operate from AA- or AAA- batteries.

CR2032 and CR2025 Lithium coin cells have higher energy density and longer shelf life. As a result, they are commonly used in low-power applications, including devices with Low Power Wi-Fi, LoRa, Sigfox, Zigbee, LTE-M1, and NB-IoT transceivers.

However, these batteries have relatively high internal resistance and chemical reaction rates that reduce their usable capacity when under pulsed-load conditions. To overcome this limitation, the NBM7100 and NBM5100 contain two high-efficiency DC-DC conversion stages and an intelligent learning algorithm.

The first conversion stage transfers energy from the battery to a capacitive storage element at a low rate. The second stage utilizes the stored energy to provide a regulated output programmable from 1.8 V to 3.6 V with a high pulse current of up to 200 mA. The intelligent learning algorithm monitors the energy used during repetitive load pulse cycles and optimizes first stage DC-DC conversion to minimize the residual charge in the storage capacitor. When not performing an energy conversion cycle in standby state the devices consume less than 50 nA.

Both devices are specified over -40 °C to 85 °C, making them suitable for commercial indoor and industrial outdoor environments. A ‘low battery’ indicator alerts the system when the battery reaches its functional endpoint. In addition, brownout protection inhibits charging of the storage capacitor when the battery is near the end of its life.

A serial interface is included for configuration and control by a system microcontroller: I2C in NMB7100A and NBM5100A and serial peripheral interface (SPI) in NMB7100B and NBM5100B versions. Both devices can extend the lifetime of energy-dense Lithium primary batteries, including coin cells, Lithium Thionyl (ex: LS14250 1/2 AA) and emerging paper printed types, thus reducing maintenance by extending the time interval between battery replacements. In addition, the NBM5100A/B includes a capacitor voltage balancing pin for super-capacitor-based implementations.

“Introducing this battery life booster product signals Nexperia’s further expansion into battery management solutions,” according to Dan Jensen, General Manager of Nexperia’s BG Analog and Logic ICs. “We are excited to unveil these innovative products complementary to our existing analog and logic products. The NBM7100 and NBM5100 significantly enhance coin cell performance which helps to help reduce battery waste in IoT, wearables and other consumer applications.”

Device Part Number

Bus Interface

Auto Start

Max Storage Cap Voltage

Max Load Current

NBM7100A

I2C

Supported

11V

200mA

NBM5100A

I2C

Supported

5.5V

150mA

NBM7100B

SPI

Not Supported

11V

200mA

NBM5100B

SPI

Not Supported

5.5V

150mA

The NBM5100A/B and NBM7100A/B battery boosters are available in a small DHVQFN16 package measuring 2.5 mm × 3.5 mm × 0.85 mm.

www.nexperia.com