Double-layer capacitors set new levels of voltage and resistance rating

July 23, 2013 // By Graham Prophet
Rohm Semiconductor has announced thin, high-output electric double layer capacitors (EDLCs) [“super-capacitors”] claiming the industry’s highest voltage at 3.0V). In addition an internal resistance of only 25mΩ at 0.7F has been achieved.

Through optimised material selection and proprietary processes, Rohm was able to achieve the 3-V rating. In addition, an internal resistance of 25 mΩ was made possible by devising a surface treatment for the collector electrode that reduced the interfacial resistance (a primary resistance factor) to zero. The result is higher voltage with less resistance, making the EDLCs sutiable for a wide variety of applications. A thin aluminium laminate package is used for higher output while also contributing to end-product miniaturisation.

Future developments will include peripheral circuits such as LED flash modules that incorporate LED elements and EDLCs by combining IC, LED, and module technologies. Rohm will also continue to increase capacitances to meet the growing needs for energy storage devices in the automotive and industrial equipment sectors.

In addition to the SR and VR Series, the VT Series will be available, which supports high-temperature operation.

Applications; Peak Assist - In applications such as LED flash that require a sudden voltage load there may be a momentary voltage drop due to insufficient battery charge. EDLCs can be used to suppress or minimise these voltage drops during large loads. In addition, the assist operation prolongs operating time and allows smaller power supplies to be used for greater device miniaturisation.

Battery Assist - In response to power interruptions, voltage fluctuations, or momentary voltage sag caused by a variety of factors, EDLCs can provide instantaneous power to prevent device failure or malfunction. They can also be used to prevent damage to the SSD and other components in PCs and similar equipment due to forced power off in the event of operation hangups.

Rohm, www.rohm.com/eu