White LED Driver Illuminates Large LCDs

Tailored to large LCDs employing an array of LEDs, the MAX8790 white LED driver integrates a current-mode step-up controller to drive six parallel strings of LEDs connected in multiple series. The string-current control circuit achieves ±1.5% regulation accuracy between strings, ensuring even brightness. Input-voltage range is 4.5V to 26V, and the device provides a fixed 20 mA or adjustable 15 mA to 25 mA, full-scale output. Other features include a feedback voltage at each LED string of 450 mV, selectable switching frequency (500 kHz, 750 kHz, or 1 MHz), two dimming control modes, separate feedback loops, cycle-by-cycle current limiting, and thermal shutdown. Available in a 20-pin, 4 mm x 4 mm TQFN package with an operating temperature range from -40°C to +85°C, prices start at $1.95 each/1,000. MAXIM INTEGRATED PRODUCTS, Sunnyvale, CA. (800) 998-8800.