White LED Drivers Increase Efficiency

Enlarging the MIC22xx family of 1.2 MHz, white LED drivers, the MIC2292 and MIC2293 are described as high-efficiency devices, aimed at applications that provide color-LCD backlighting in cellular phones, PDAs, and digital cameras. They are 1.6-MHz and 2-MHz PWM dc/dc drivers, respectively, requiring four external components to design a complete white LED driver circuit. These include two ceramic capacitors (input and output), an inductor and a resistor to set the LED current level. Both devices integrate a 34V switch that can handle more than 0.5A of current and are available in 2 mm x 2 mm MLF-8L packages. Prices start at $1.25 each/1,000. MICREL INC., San Jose, CA. (510) 476-5963.