News and New Products

Nanotech supercapacitors up voltage, operating temperature

By Margery Conner, Technical Editor -- EDN, 9/18/2007

Supercapacitors combine the energy-storage capability of batteries with the rapid charge and discharge times of capacitors. They are good matches for applications with periodic pulsed loads that draw greater power than a battery can provide, such as LED flashes, autofocus motor drives for cameras, and cell-phone audio. Cap-xx has introduced the high-temperature HS and HW line of supercapacitors that bumps up the operating voltage from 4.5 to 5.5V and extends the operating and storage temperature from 75 to 85°C. Tolerance of high temperatures is important in supercapacitors for consumer electronics, such as those in vehicles sitting in direct sunlight or next to a heat-producing component, such as an RF power amp. Power densities are as high as 71.5 kW/l, and energy densities are as high as 1.5 Whr/l.

The HW series has a footprint of 28.5×17 mm, a height of 0.9 to 2.90 mm, capacitance as great as 0.4F at 5.5V, and ESR (equivalent-series resistance) as low as 110 mΩ at 5.5V. The HS series has a footprint of 39×17mm, capacitance as great as 0.7F, and an ESR as low as 55 mΩ at 5.5V. You can solder or ultrasonically weld the low-profile, prismatic packages to pads on a PCB (printed-circuit board). Pulse current for a single pulse is 20A; rms current is 4A. Prices start at less than $2 each (production quantities).