Recently, Vishay Intertechnology, Inc. announced the launch of two new 1.25MHz current mode boost converters optimized for white LED applications. The new SiP12510 and SiP12511 devices have an input voltage range of 2.5V to 6.0V, the SiP12510 has an output voltage of up to 17V, and the SiP12511 has a maximum input voltage of 28V.
These new devices in the SOT23-6 package provide a small LED driver solution that requires minimal external components. Both the SiP12510 and SiP12511 feature an internal integrated power switch and operate on a 1.25MHz high frequency conversion oscillator. This allows the use of small inductors, which reduces the required board space.
This comprehensive LED driver solution integrates multiple protection features including overvoltage protection and 0.55A cycle-by-cycle current limit, supporting up to three parallel strings, each 20mA. The thermal shutdown block provides another protective layer by turning off the device when the internal temperature exceeds a typical temperature threshold of 165 °C.
To achieve full control of LED illumination intensity, the SiP12510 and SiP12511 support linear and PWM technology that regulates LED string current. The built-in three-phase soft-start feature reduces the peak current required during startup by gradually increasing the switching current limit.
Each device implements a low feedback voltage of 0.1V and a tight switching frequency to achieve higher conversion efficiencies over the full industrial operating temperature range of -40°C to +85°C.
Combining 90% efficiency, less than 1μA shutdown current, and small footprint, the SiP12510 and SiP12511 are ideal for space-constrained, battery-powered portable applications such as cell phones, PDAs, and digital cameras.
Samples of the new SiP12510 and SiP12511 are available now, and volume production quantities are available in the second quarter of 2007. The lead time for major orders is 13 weeks.
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