Six-channel PCB balances supercapacitors for energy harvesting

The PCB can balance any size of supercapacitor with zero added power dissipation, says the company, and is able to balance up to six supercapacitors stacked in a series, with capacities from 0.1 to 3,000 Farads and from 12V and above. Robert Chao, president and founder of ALD, said: “Leakage current can be affected by many parameters in a supercapacitor, such as operating temperature, aging, initial leakage current input voltage, and the operating bias voltage.”  The low power dissipation enables energy-efficient supercapacitor balancing.  

Targeting 12V battery applications, where six 2V cells are increasingly used, developers are often required to stack supercapacitors in series or in parallel. Stacking up to six connected cells, reduces the risk of a short circuit and battery failure.

Each six-channel PCB is populated with three ALD9100XX SABMOSFETs that automatically balance the leakage and voltage of each supercapacitor cell connected in series. Optional reverse-biased external clamping power diodes (Schottky rectifiers) can be installed when necessary across each SAB MOSFET to clamp surge current transients. The company also offers a blank SABMB6 PCB for customers to insert their own SAB MOSFETs.

The PCB is added to the company’s portfolio which includes two- and four-channel SAB PCBs, the SABMB2 and SABMB16. No electrical engineering expertise or board design is required to use the boards, says the company – the user only has to mount the PCB and wire the appropriate connections from the board to the respective supercapacitor nodes.

The two-, four- and six-channel boards can be mix-and-match configured and cascaded to balance multiple series stacks.

The compact SABMB6 PCB is made from RoHS-compliant FR4 material, and measures 0.6 × 1.6 inch (15.24 × 40.64 mm). It is rated for operation at the industrial temperature range of -40 to +85°C. It is available from distributors Mouser and Digi-Key.