Date: 03/05/2009

LED drivers accustomed to supercapacitors

Power semiconductor device vendors are offering LED drivers specifically designed for supercapacitors. Supercapacitors, which are also called ultracapacitors can store large quantity of electrical energy with some physical and mechanical advantages over batteries.

LED flash drivers, which need high level of power for short duration, are going for supercapacitor/ultracapacitor as power source. The supercapacitor manufacturer CAP-XX has named few latest led drivers supporting supercapacitor based flash. They include AnalogicTech's AAT1282, and ON Semiconductor's CAT3224 and yet-to-be-released NCP5680 supercapacitor-optimized LED flash drivers.The LED flash driver reference designs are available from Seoul Semiconductor and ON Semiconductor.

LED driver with supercapacitor can drive high-current white LEDs (WLEDs) by occupying far lesser space in comparison to outdated xenon flash. These LED flash drivers integrate all circuitry required to charge the supercapacitor, manage in-rush current and control LED current.

White LED based flash generate enough light to capture clear images in digital cameras, but need up to 400% more power than a battery can provide. To support the battery, a thin supercapacitor can drive the LED flash to full intensity while also handling other peak-power needs - zoom, auto-focus, audio, video, wireless transmissions, GPS readings and RF amplification - without compromising slimline design.
BriteFlash from CAP-XX combines an LED flash driver IC, supercapacitor, battery and WLEDs. The flash driver's boost converter charges the supercapacitor to 5.5V, which then delivers high-peak current to drive the LED flash. The battery only supplies average power, and recharges the supercapacitor between flashes.
There is a whitepaper available for designers to learn more on this article subject, it can be downloaded from http://www.cap-xx.com/resources/pres_wp/pres_wp.htm#wp