Fractional Charge Pump Drives up to Four LEDs
Tue, 01/22/2008 - 5:53am
Power efficiency up to 92% ’604-compatible with added benefits Eliminate Unwanted EMI
Catalyst Semiconductor, Inc. has launched its newest Quad-Mode fractional charge pump LED driver, the CAT3604V a four-channel LED driver, which provides an alternative to the industry-standard ’604 with similar functionality and the added benefits of Catalyst’s patented Quad-Mode switching architecture, including improved average efficiency. Quad-Mode technology delivers the high efficiency levels normally associated with inductor-based LED drivers, while eliminating the associated high-profile inductors and unwanted EMI. Most charge pump LED drivers today offer three modes of operation corresponding to the ratio of the output voltage to the input voltage: 1x, 1.5x and 2x. The Quad-Mode architecture of the CAT3604V adds a fourth mode of operation, 1.33x, to deliver the higher average efficiency, without the need for the additional capacitor required by all existing four-mode charge pumps. The 1.33x fractional operating mode also reduces the input switching currents seen at the battery, minimizing the overall supply noise – a critical parameter in portable devices such as cell phones.
fractional charge pump LED driver