ALD's PCB auto-balances leakage current in supercapacitor stacks



ALD's PCB auto-balances leakage current

Advanced Linear Devices, a design innovation leader in analog semiconductors, announced the immediate availability of universal printed circuit boards(PCB) designed to automatically balance leakage currents and manages over voltage enabling ultra-low power usage in supercapacitors used in a series stack. The board uses ALD’s SAB MOSFETs to balance the leakage current in each individual supercapacitor cells, even for cell of 3000 Farad (F) or more.

The PCB is designed to allow system engineers to test, evaluate, prototype or use in production products. Supercapacitor balancing is required by cell manufacturers when used in stacks of two or more . Balancing manages over-voltage limits, a main cause of product failures. Additionally, the SAB MOSFET’S PCB balancing technology reduces leakage current enabling ultralow power operation. Each device in the ALD8100XX/ALD9100XX SAB MOSFET provides a superior circuit design alternative to passive or active balancing methods by offering automatic active leakage current regulation and space and cost-saving alternative to op-amp based balancing schemes.

Engineering testing shows the ALD method of cell balancing extends the product life of stacked caps. Industries such as energy harvesting, transportation, back-up power and automation applications are beginning to include supercapacitors.

ALD offers a family of printed circuit boards: SABMB16/SABMB810025/SABMB910025 are universal application boards. The first two versions in the series are SABMB810025 and SABMB910025. These are 2.5-volt universal boards allowing designers to select either the ALD810025 SAB MOSFETs or the ALD910025 SAB MOSFETs installed. A third version is unpopulated to allow engineers to select the appropriate SAB MOSFETs based on their specific design specifications. All three options are delivered ready to use, designed for compact, economical and effective balancing any size supercapacitors with little or no power dissipation. . No user circuit design or hardware engineering is necessary.

The charging or discharging of supercapacitor currents pass through the supercapacitors themselves, but do not pass through the SABMB16 boards or SAB MOSFETs mounted on the PCB board. In many cases, the total additional leakage current contributed by the PCB is approximately zero, or no more than a small percentage of the highest supercapacitor cell leakage current in the stack. This contrasts with other methods of balancing where the additional power dissipation used by the balancing circuitry far exceeds the supercapacitor power burn caused by its own leakage current.

“The rapid pace of innovation for new supercapacitor applications is accelerating especially for those using two or more cells in a series stack as high-current energy storage devices for industrial pioneering systems,” said Robert Chao, President and CEO of Advanced Linear Devices Inc. “These boards are designed to give developers a superior way to balancing supercapacitors, protecting them from over-voltage and over-current situation, saving energy, extending their useful life and preventing pre-mature field failures.”

SABMB16 is designed for ease of use as a plug-and play PCB for supercapacitors of 0.1 farad (F) 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.

Pricing and Availability
Products can be ordered directly from ALD or ordered from DigiKey or Mouser. Quantities start at $33.34 for single unit.

Advanced Linear Devices