Nexperia unveils coin cell battery life and power booster

Nexperia has introduced the NBM7100 and NBM5100, new types of battery life boosting ICs designed to extend the life of a typical non-rechargeable lithium coin cell battery.

According to Nexperia battery life can be extended by up to 10x compared to competing solutions while also increasing its peak output current capability by up to 25x compared to what a typical coin cell can deliver without a battery booster. 

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 and, 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.

These batteries, however, 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 utilises the stored energy to provide a regulated (programmable from 1.8 V to 3.6 V) high pulse (up to 200 mA) current output.

The intelligent learning algorithm monitors the energy used during repetitive load pulse cycles and optimises first stage DC/DC conversion to minimise the residual charge in the storage capacitor. When not performing an energy conversion cycle (standby state), these 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, 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.