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New LED driver from austriamicro

Posted: 02 Sep 2005 ?? ?Print Version ?Bookmark and Share

Keywords:austriamicrosystems? led driver? as3691?

austriamicrosystems extended its LED driver family with the release of the AS3691 4x400mA LED driver, designed for the fast-growing high and ultra high brightness LED application market.

"The strong growth in high-brightness LED applications is currently served by universal LED driver ICs leading to suboptimal solutions," said Alexander Harrer, Sr. V.P. and GM of the communications business unit at austriamicro. "The AS3691 is ideally suited for white and color high brightness LED applications since it supports very high currents, and delivers outstanding accuracy with great flexibility and efficiency, while being very simple to use."

The new LED driver includes four independent high precision current sources each capable of sinking 400mA. The operating current per LED channel can be set easily via an external resistor while the LED brightness is controlled by four independent pulse width modulated inputs. The four independent current sinks per chip enables the device to drive either four white LEDs each sinking 400mA or a single white LED with up to 1.6A.

According to Ronald Tingl, marketing manager for power and lighting management at austriamicrosystems, the AS3691's absolute current accuracy of 0.5 percent allows for highly accurate brightness settings. "This is ideal for support sophisticated color management applications like LCD monitors with RGB backlighting," Tingl said.

"With four independent current sinks available, the AS3691 offers great flexibility in combining various color LED settings such as RGGB or RGBA strings. The current sources have a wide voltage compliance range of 15V and special internal circuitry allows for very high LED supply voltages that are limited only by the maximum power dissipation allowed for the entire application," Tingl added.

The AS3691's linear driver avoids issues that are typical of inductive boosters, like EMI, or flickering images that are particularly critical in LCD monitor applications. And to optimize the application's power efficiency, each channel includes a feedback output that enables simple adjustment of one or more external power supplies allowing overall power dissipation to be kept at a minimum.

The AS3691 is available in a small QFN4x4 package or as a die-only solution.

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