19-1621; Rev 2; 2/07 High-Efficiency Step-UpCurrent Regulator for LEDsMAX1698/MAX1698AGeneral DescriptionFeatures The MAX1698 and MAX1698A are efficient drivers for ♦ Over 90% Efficiency white or color LEDs. They are ideal for large LED backlit displays in PDAs and laptop computers. Numerous ♦ Lossless, Adjustable LED Brightness benefits include greater simplicity, lower cost, higher ♦ Space-Saving 10-Pin µMAX Package efficiency, longer bulb life, and greater reliability when compared to fluorescent (CCFL) and electrolumines- ♦ Simpler, Lower Cost, More Reliable Compared cent (EL) lamps. to CCFL or EL Backlights The MAX1698/MAX1698A are switch-mode boost con- ♦ Up to 5W Output Power trollers in which LED current, rather than output voltage, is regulated The devices drive series-connected LEDs with a controlled current that is measured with a typical- Ordering Information ly 15Ω sense resistor, not an expensive fractional-ohm PIN -PKG value. LED current control and dimming are accom- PARTT EM P RA N G EPA C K A G ECODE plished with an adjust input (ADJ). For larger light out- put, multiple LED banks can be connected in parallel MAX1698 EUB -40°C to +85°C 10µMAX U10-2 with up to 5W total output power. MAX1698A EUB -40°C to +85°C 10µMAX U10-2 The MAX1698A has a higher, and more accurately specified, CS current limit than the MAX1698 for higher- Pin Configuration power applications of 5W or more. Both devices are supplied in a space-saving 10-pin µMAX package that TOP VIEW occupies half the space of an 8-pin SO. An evaluation kit (MAX1698EVKIT) is available to speed designs. VCC 1 10 EXT Applications SHDN 2 9 CS MAX1698 Battery-Powered Backlight Applications REF 3 8 PGND MAX1698A Backlight for LCD Panels ADJ 4 7 GND Notebook PCs GND 5 6 FB Handy Terminals µ MAX PDAs Typical Operating Circuit L V D1 BATT VOUT COUT VCC VCC EXT MAX1698 ON MAX1698A OFF SHDN CS ILED REF PGND ADJ FB GND RFB RN ________________________________________________________________ Maxim Integrated Products1For pricing delivery, and ordering information please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
