Malvern, Pa. Vishay Intertechnology, Inc. has released two 1.25-MHz current-mode boost converters optimized for white LED applications. The SiP12510 and SiP12511 white LED drivers offer a 90% typical efficiency, said to be the highest rating for this type of device.
The SiP12510 and SiP12511 white LED drivers feature an input voltage range of 2.5 V to 6.0 V, and output voltages of up to 17 V for the SiP12510 and 28 V for the SiP12511. With their combination of 90% efficiency, less than 1 microamp shutdown current, and a small footprint, the SiP12510 and SiP12511 are particularly suited for space-constrained, battery-operated, portable applications such as cell phones, personal data assistants (PDAs), and digital cameras.
This complete LED driver solution integrates several protection features including over-voltage protection and a cycle-by-cycle current limit of 0.55 A supporting up to three parallel strings of 20 mA 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.
Pricing: $1.08 each for U.S. delivery in quantities of 1,000.
Availability: Samples of the SiP12510 and SiP12511 are available now. Production
quantities will be available in second quarter 2007, with lead times of 13 weeks for
Datasheet: SiP12510 and SiP1251
Vishay Intertechnology, 1-619-336-0860, www.vishay.com