Vishay Intertechnology, Inc. announced the release of two new 1.25MHz current-mode boost converters optimized for white LED applications. The new SiP12510 and SiP12511 devices feature an input voltage range of 2.5 to 6.0V, and output voltages of up to 17V for the SiP12510 and 28V for the SiP12511.
Offered in the SOT23-6 package, the new devices are claimed to offer a compact LED driver solution requiring minimal external components. Both the SiP12510 and SiP12511 are equipped with an internal integrated power switch and run on a high-frequency 1.25-MHz switching oscillator. This allows the use of a small-size inductor, reducing the required board space. The LED driver solution integrates several protection features, including overvoltage protection and a cycle-by-cycle current limit of 0.55A supporting up to three parallel strings of 20mA each. A thermal shutdown block provides another layer of protection by shutting down the device once the internal temperature exceeds the 165°C typical temperature threshold.
To enable full control over LED illumination intensity, the SiP12510 and SiP12511 support both linear and PWM techniques for regulating the LED string current. A built-in three-phase soft-start function diminishes the required peak current during start-up by gradually increasing the switch current limit. Each device implements a low feedback voltage of 0.1 V and a tight switching frequency, resulting in improved conversion efficiency over the full industrial operating temperature range of -40 to +85 °C. With their combination of 90% efficiency, less than 1µA shutdown current, and a small footprint, the SiP12510 and SiP12511 are particularly suited for space-constrained, battery-operated, portable applications such as cell phones, PDAs, and digital cameras.
Samples of the new SiP12510 and SiP12511 are available now. Production quantities will be available in Q2 2007, with lead times of 13 weeks for larger orders.
