Sunnyvale, Calif.—Catalyst Semiconductor's Quad-Mode adaptive fractional charge pump, which can drive up to six white/color LEDs, delivers high efficiency—close to those of inductive boost converters, at no extra cost and in a best-in-class footprint.
"There are three considerations for designers of LED backlighting solutions for handheld products: Size, efficiency and cost. The CAT3636 manages to combine a best-in-class footprint with previously unheard-of efficiency at no price premium....what many people previously thought was impossible," said Scott Brown, vice president of marketing.
With the Quad-Mode switching architecture and TQFN package, the new CAT3636 delivers efficiency levels as high as 92 percent (lifetime average efficiency 84 percent) for razor-thin portable products, while eliminating the usual high-profile inductors and EMI. Today's typical charge pump LED driver offers three modes of operation corresponding to the ratio of the output voltage to the input voltage: 1x, 1.5x and 2x. The CAT3636's Quad-Mode architecture adds a fourth 1.33x mode of operation, without the need for an additional charge pump capacitor, to boost efficiency by 10 percent over traditional tri-mode designs. This design also cuts input switching currents seen at the battery, thus minimizing the overall supply noise.
The CAT3636 includes six LED current sinks configured into three separate banks (32 mA each), with each bank containing a pair of tightly regulated and matched output channels. Fully featured programmability and dimming control is achieved via the company's 1-wire EZDim programming interface, which allows the user to accurately set LED banks individually.
The product datasheet will be available shortly. The CAT3636, in a 3-by-3 mm, low-profile 16-pin TQFN RoHS-compliant package, is priced at 94 cents each in 10k quantities. Samples and evaluation kits are now available. Projected lead-time for production quantities is currently 6 to 8 weeks ARO.
Catalyst Semiconductor, 1-408-542-1000,