Nexperia Gives Coin-cell Batteries Big Surge With Battery-boosting ICs

Nexperia has announced a new coin-cell battery life and power booster to enable another power source for IoT and wearable electronics. The two ICs, the NBM7100 and NBM5100, both offer improved battery life and power output for devices that would normally be limited by the coin cell’s internal resistance, making it highly beneficial for small, battery-powered electronics.

 

The NBM7100 and NBM5100 both offer considerable increases in battery life for coin-cell-powered electronics, allowing for smaller designs. Image (modified) used courtesy of Nexperia

 

Distributed sensor/communications nodes consume very little power on average. Wireless communications, however, typically require short bursts of higher power, requiring a low internal resistance battery to function correctly. With the Nexperia architecture, a higher-resistance battery, like a coin cell, can be used without issue.

To give readers a sense of the chips’ capabilities and novelty, this article summarizes the key specifications of the new Nexperia products and discusses how they can be used to add much more versatility to small devices.

 

A Smaller Battery Power Solution

With advancements in the IoT, wearable electronics, and distributed sensor networks driving a push toward smaller, low-power devices, many developers are exploring different power solutions, such as RF at-a-distance charging or near-field power transfer, to find a scalable architecture for large networks. While battery power is a popular solution, periods of high power consumption that are common in wireless communications typically require larger and less resistive batteries. The new Nexperia chips are claimed to solve this problem for coin-cell batteries.

 

The NBM7100 reports a >90% efficiency at high operating currents, enabling designers to make the most of the power provided by the coin-cell battery. Image used courtesy of Nexperia

 

The NBM7100 and NBM5100 support a maximum output current of 200 and 150 mA, respectively, with corresponding max storage capacitor voltages of 11 V and 5.5 V and efficiency near 100 mA above 90%. I2C and SPI interfaces allow designers to interact with the power converters onboard. Multiple modes and additional features are included in the product line, including autostart functionality in the NBMXXXXA series.

 

Smart Voltage Conversion

The NBM series offers effective battery management by leveraging the bursty nature of the overall current consumption. When the load is not enabled (for example, when the sensor is not transmitting), the IC draws a constant current from the battery to slowly charge an external capacitor. Once a higher current is needed, the capacitor drives a buck converter to efficiently provide the current pulse without increasing the load on the battery. The chips also provide a “permanent output” to ensure that low-current electronics such as microcontrollers always receive power.

 

The system-level block diagram highlights the method that the converters use to regulate the output of the battery and the optimizer to find the best operating point. Image used courtesy of Nexperia

 

Nexperia reports a high overall efficiency for the converters, with values above 90% at key load currents. The chips can accomplish this by using a learning algorithm to optimize the first DC-DC converter stage. Furthermore, the standby modes ensure an extremely low current consumption when not in use, with the devices drawing less than 50 nA in standby.

 

Distributed Battery-powered Electronics

The latest Nexperia battery management chips not only complement the greater Nexperia power IC product line but also offer designers a new and unique power solution for dense and highly-integrated electronics. And while battery power may not be practical for every application, these two chips add new tools to a designer's disposal when considering power sources.