Components

Equalizing Leakage Current to Balance High-Voltage Supercapacitors

Advanced Linear Devices Inc. (ALD) announced a high-voltage supercapacitor balancing printed circuit board (PCB) designed to automatically control leakage current and enhance reliability for applications used in data center, industrial automation, public utility, and transportation systems.

ALD SABMB810028 boards built with ALD810028SCLI SAB MOSFETs provide balancing for 2.8V, 3.0V and 3.3V supercapacitors arranged in a series stack by equalizing the leakage current of each cell.

ALD SAB MOSFET arrays used in each board provide industry’s most scalable, low-power solution. Additionally, the MOSFETS balance each cell through low levels of leakage current without exposure to supercapacitor charge/discharge voltage levels for cells of 3000F or more.

“New higher voltage supercapacitors being introduced to address the energy storage needs of data centers and industrial automation require high reliability to meet very demanding standards for backup power systems,” said Robert Chao, President and Founder, Advanced Linear Devices Inc.

“These boards provide the ideal platform for balancing high voltage supercapacitors through a low-voltage, low leakage and low current controlling method in a small and scalable form factor,” Chao continued.

SABMB9100 schematic diagram (click on image to enlarge)

ALD SABMB810028 boards are rated for -40 to +85 degrees C and are available with the following voltage ratings:

  • 8V with 1µA operating current;
  • 3V with 100µA operating current;
  • 3V with 1,000µA (1 milliamp) operating current.

In many cases, the operating current is equivalent in magnitude to the leakage current of the supercapacitors.

Overvoltage is a leading cause of failures for supercapacitors. Design engineers need to balance all supercapacitor cells in a stack of two or more to fight overvoltage. ALD’s SAB MOSFET(s) installed on the board play a vital role in preventing overvoltage, and the boards enable system engineers to test, evaluate, prototype or enter production volume.

ALD SAB MOSFET technology provides a superior circuit design to other passive or active balancing scheme through superior cost and design space options for  supercapacitor leakage currents.

The boards are scalable to meet the growing application of multiple supercapacitor cells in modules to meet the energy storage needs of higher voltage systems. Engineers looking to meet the needs of new 700-V systems, for example, could arrange 64 ALD SABMB810028 boards together to ensure safe voltage balancing.

The ALD SAB MOSFET boards allow supercapacitor cell charging and discharging currents to pass through the cells themselves directly, bypassing SAB MOSFETs mounted on the board with near zero additional leakage current, a superior alternative to other methods where additional power dissipation used by the circuitry far exceeds the supercapacitor energy burn caused by leakage currents.

SABMB810028 board is designed for ease of use as a plug-and-play PCB for supercapacitors of 0.1F to 3000F and beyond. The average additional power dissipation due to dc leakage of the supercapacitor is zero, which makes this method of supercapacitor balancing highly energy efficient and well suited for low-loss energy harvesting and long-life battery operated applications.

Products can be ordered directly from ALD or ordered from online distributors DigiKey or Mouser. Prices start at $30.17 each for boards ordered in volume. boards.

Advanced Linear Devices Inc.
To Top

Join 50,000+ Power Pros

 

  • Keep pace with relentless innovation
  • Influence the conversation
  • Take your insights to another level

You have Successfully Subscribed!