Robert Chao, president and founder of ALD Inc. just engineered and introduced a board that enables leakage current balancing for 12-volt systems used in automotive, gap power and remote monitoring applications.
The board is a six-channel supercapacitor automatic balancing (SAB) PCB. The SABMB6 balances any size of supercapacitor with zero added power dissipation. Each of these PCBs are able to balance up to six supercapacitors stacked in series, ranging in size from six to hundreds of supercapacitors with capacities from 0.1 to 3,000 Farads in voltages of 12 and higher. The design offers ultra-low power dissipation which enables energy-efficient supercapacitor balancing This is ideal for applications that require low-loss energy harvesting, long life, and battery backup or replacement.
The design does not focus on the DC voltage balancing; instead, the ALD method manages leakage current and is independent of the cell capacitance. 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.
12V battery applications are well suited for this kind of tool. Where six 2V-cells are increasingly used, developers are often required to stack supercapacitors in series or in parallel. This board allows up to six connected cells, reducing the risk of a short circuit and battery failure.
Each six-channel PCB is populated with three ALD9100XX SAB MOSFETs 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. ALD also has a blank SABMB6 PCB for customers to insert their own SAB MOSFETs.
ALD already has two- and four-channel SAB PCBs, the SABMB2 and SABMB16. The boards can be cascaded with mix-and-match configurability to balance multiple series stacks, i.e. combining ALD’s two-, four-, and six-channel PCBs as required.
This is a simple, out-of-the-box, plug-and-play PCB solution reducing time-to-market for existing and emerging applications. No electrical engineering expertise or board design is required; the user has only to mount the PCB and wire the appropriate connections from the SABMB6 board to the respective supercapacitor nodes.
The compact 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 +85o C. The product can be used for evaluation, prototyping, or production. Prices range from $12.20 to $38.97 each.
Visit the ALD website for more information.