Austriamicrosystems’ AS3685 is an ultra-small, safe, simple and fully integrated 700mA charge-pump-based flash LED driver. Said to be the world's smallest fully integrated flash LED driver offering 700mA flash current, it is targeted at camera flash applications in mobile phones.
Almost 50% of today's mobile phones offer cameras, and an increasing number of camera phones are equipped with flash LEDs. As the resolution of image sensors is expected to exceed two megapixels for mainstream phones in 2007, demand for a strong LED flash to take quality pictures is growing. Designing LED based flash functions with currents in the 700mA range has a significant impact on power consumption, especially in modern mobile phones which tend to include a wide variety of fashionable but power-hungry features such as video streaming, MP3 or WiFi. The LED driver needs smart power management to stay within the overall power budget, even under the most demanding conditions such as replying to RF signals while taking pictures.
The wafer-thin AS3685 measures only 2x1.5mm, with a height of 600µm. It takes up just 14mm2 of PCB space, including four external components. Following 0.25mm PCB design rules, the driver is said to use less than 50% of the space required by its closest competitor. The only external components that the AS3685 needs are low cost capacitors and resistors. This gives the device an excellent overall bill of material (BOM) and outperforms competing inductive solutions by at least 20%.
Austriamicrosystems, www.austriamicrosystems.com
