Design Tools for LEDs in Camera Phones

CAP-XX Limited announced availability of supercapacitor-optimized LED flash drivers from several power management integrated circuit (PMIC) companies to facilitate design of high-power LED flash units for high-resolution camera phones and digital cameras.

AnalogicTech's AAT1282, and ON Semiconductor's CAT3224 and soon-to-be-released NCP5680 supercapacitor-optimized LED flash drivers team with today's high-current white LEDs (WLEDs) in a thin-form solution which provides comparable light energy to a bulky xenon flash. These LED flash drivers integrate all circuitry required to charge the supercapacitor, manage in-rush current and control LED current.

To produce high-resolution pictures in low-light conditions, cameras of 5 or more megapixels require a high-intensity flash. Today's WLEDs can deliver such light energy, but need up to 400% more power than a battery can provide. To support the battery, a 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 the form factor.

BriteFlash 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.