White LED Flash Drivers Offer Alternative To Xenon Lamps August 29, 2008
Supporting either two white LEDs requiring up to 750 mA each or one LED up to 1.5A, the AAT1271 and AAT1272 dual-channel boost converters feature the company’s proprietary AS2Cwire and industry-standard I2C interface, respectively. The two buses allow designers to modify drive current and, therefore, LED brightness. Available in 3 mm x 3 mm TDFN packages, they offer an alternative to larger xenon lamp packages. Both devices accept a 2.7V to 5.5V input voltage, employ a 2-MHz switching frequency, and can achieve up to 85% efficiency with 1-µH inductors. Other shared features include two channels capable of drive currents up to 750 mA each and separate flash enable and movie-mode enable inputs. The AAT1271 provides the proprietary single-wire AS2C interface while the AAT1272 offers the industry-standard two-wire I2C interface and the AAT1271 also adds a flash inhibit input. Price for either device is $1.49 each/1,000. ANALOGIC TECHNOLOGIES INC., Sunnyvale, CA. (408) 737-4600.
