CAP-XX Inc. today announced itsBriteFlash power architecture to provide LED flash camera phones withenough light to produce high-resolution images. Some phone manufacturershave experimented with long flash exposure times to compensate forlow-light problems, which then results in blurry photographs. CAP-XX'sBriteFlash architecture provides enough flash power to eliminate both darkand blurry photos using high-capacitance (0.4 to 1 farad), lowequivalent-series-resistance (less than 100 milliohms), thin (1 to 3millimeters) prismatic supercapacitors to support a battery and deliver thepulse power to drive an LED to full light intensity. CAP-XX also developedthe power architecture that optimizes a supercapacitor to power flash LEDs.

"Greater than 2-megapixel camera phones require ahigh-intensity flash in medium to low light conditions to ensure goodpictures," said Anthony Kongats, CEO of CAP-XX. "Some solutions areavailable but lack adequate power to produce quality photos in all lightconditions. Our BriteFlash power architecture completes the equation withthe power to drive today's LEDs."

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As a technology demonstration of its BriteFlash solution,

CAP-XX engineers retrofitted this industry-leading camera phone

by adding a 1.2mm-thin dual-cell supercapacitor

[highlighted], and replacing existing LEDs with 4 high-powered

LEDs. The original phone delivered 1 watt

of flash power for 160 milliseconds while the CAP-XX-modified

phone delivered 15 watts of flash power for 160 milliseconds.

Today's high-power white LEDs require a higher voltage than a Li-ionbattery can supply, so power integrated circuit (IC) suppliers havedeveloped special-purpose DC/DC and charge pump ICs to drive these LEDs.However, these new LEDs need up to 400% more power than a battery canprovide to achieve full light intensity. CAP-XX supercapacitors candeliver this pulse power. CAP-XX has developed reference designs usingstandard flash drivers that offer multiple design options.

The CAP-XX BriteFlash power architecture is similar to a Xenon flashsolution used in digital cameras today, where a low-current charge pump(boost converter) charges the supercapacitor to 5.5 volts then thesupercapacitor drives the LED at very high current for the flash pulse.CAP-XX's supercapacitor-based solution, however, delivers more light energy(flash power x flash duration) and has a much thinner form factor than theXenon one. Designers are forced to choose thinner, hencereduced-capacitance 330-volt cylindrical electrolytic storage capacitorsnecessary in Xenon designs to fit them in space-constrained camera phones.Thesereduced-capacitance electrolytic capacitors, which are still bulky at 6 to10 millimeters, reduce the light energy the flash can provide.

Two BriteFlash solutions described here allow tradeoffs between the flashdistances needed to take high-resolution photos, and the cost to implementthem. Solution 2 yields an effective flash up to 1.5 meters versus the 3meters achieved with the maximum power in Solution 1.

Technical Specifications:

Solution 1 offers maximum power and supports a flash photo up to 3 meters,compared to 1 meter or less for camera phones without a supercapacitor inlow lighting. A dual-cell supercapacitor such as a 0.55-farad, 50-milliohmCAP-XX GS206 delivers over 25 watts to the LEDs versus 2 to 4 watts withouta supercapacitor. A supercapacitor also eliminates the need to shut downthe rest of the phone because the battery isn't needed to supply anycurrent during the flash, leaving it free to supply other power needs suchas OLED display or RF transmission. The battery only needs to provide alow-charging current of 250 mA to the supercapacitor to support a recoverytime between flashes of approximately 2 seconds. This is less time thanthe LED needs for thermal recovery between flashes. Thelow-charging current allows designers to use lower-cost, smaller boostconverters or charge pumps because the supercapacitor supplies the peakcurrent. Without a supercapacitor, the boost converter has to be sized forpeak flash current. The CAP-XX BriteFlash reference designs show how tooptimize the power subsystem with a supercapacitor.

Solution 2 supports a flash photo up to 1.5 meters using a single-cell,lower-cost supercapacitor such as a CAP-XX GW101, which is half the volumeof the GS206 device. This solution increases the LED current byapproximately 40%, which allows the 50% increase in flash distance. Thesupercapacitor is pre-charged prior to a flash pulse and the battery onlyneeds to provide a relativelylow-charging current of a few 100mA allowing an even smaller and lower-costcharge pump than Solution 1.

Feasibility Experiment:

To demonstrate the increased flash power and ease of design-in, CAP-XXengineers retrofitted several models of industry-leading camera phones withthe BriteFlash solution. In one example, CAP-XX placed a dual-cellsupercapacitor, replaced existing LEDs with 4 high-powered LEDs that caneach handle a peak pulse current of 1A, then put the phone together againwith no changes in external appearance. The original phone delivered 1 wattof flash power for 160 milliseconds while the CAP-XX-modified phonedelivered 15 watts for the same amount of time.

Price and Availability:

The total cost of the CAP-XX BriteFlash solution is US $4 to $5 includingthe LEDs, supercapacitors and circuitry. The supercapacitor alone costs$1.50 for the single-cell solution and $2.50 for the dual-cell one inquantities of 10,000 or more.

CAP-XX is working with flash/LED driver suppliers to developsupercapacitor-optimized charge pump LED drivers to further increase cameraphone power subsystem integration and reduce costs.

About CAP-XX:

CAP-XX Inc. develops and manufactures supercapacitors. Supercapacitors canbridge the gap between capacitors and batteries, delivering higher powerbursts than batteries and storing more energy than traditional capacitors.CAP-XX has been recognized for its nanotechnology process for producinghigh capacitance, low equivalent-series-resistance supercapacitors thatdeliver the industry's highest energy and power densities in the smallestpackages.

These energy-storage devices enable manufacturers to make smaller, thinner,longer-running portable electronics such as cell phones, PDAs, medicaldevices, AMRs and notebooks. The private company is based in Sydney,Australia, has additional production facilities in Malaysia, and salesoffices in South Carolina and Texas, USA and Taipei, Taiwan. For moreinformation visit http://www.cap-xx.com or send email to sales@cap-xx.com.

Note: For block and circuit diagrams, system power breakdown andphotographs: http://www.cap-xx.com/news/photogallery.htm

CONTACT:Michelle MoodyMoody & AssociatesEmail Contact+1-214-363-3460

SOURCE: CAP-XX Inc.

Source: marketwire