Boost Converter Drives Up To 10 White LEDs

A high-efficiency dc/dc boost converter for driving white LEDs and biasing Notebook PC LCD panels is targeting portable, low-input voltage applications. The MIC2145 has a 2.4V to 16V voltage range and a low shutdown current of less than 1 µA. With an integrated 1.5A switch, the converter can drive four white LEDs for cellular applications, or up to 10 white LEDs for larger panel PDA applications. With a unique peak current set feature, designers can program the peak switch current to any level, allowing for maximum efficiency. In notebook PC applications, the MIC2145 boosts the readily available 3.3V or 5V supply to provide the required LCD bias for TFT displays. Its soft-start feature reduces power supply noise associated with in-rush current and its separate analog and power grounds further minimize noise. The MIC2145 can be configured for use in boost, SEPIC and flyback applications. It is available in an MSOP-8 priced at $2.30 each/1,000.