Linear Tech dc/dc converter delivers 500mA

The LTC3251 inductorless, spread spectrum step-down dc/dc converter from Linear Technology Corp. is capable of delivering up to 500mA of continuous output current from an input of 2.7V to 5.5V, making it suitable for use in single cell Li-ion or multicell NiMH/Alkaline applications.

The output voltage is resistor programmable from 0.9V to 1.6V enabling it to drive low voltage DSPs and microcontrollers. Switched capacitor fractional conversion enables the LTC3251 to attain efficiencies as high as 88 percent, slightly lower than that of an equivalent buck switching regulator.

Available in a thermally-enhanced 10-lead MSOP casing, the LTC3251 is claimed by the company to utilize the power industry's first 2-phase spread spectrum switching architecture to provide a very low noise regulated output as well as low noise at the input.

The switching frequency randomly shifts within the 1MHz to 1.6MHz frequency range, to minimize harmonic switching spikes that can introduce noise into nearby RF circuitry.

The IC operates either at continuous spread spectrum, spread spectrum with Burst Mode operation, Super Burst mode, and shutdown. At Burst Mode and Super Burst Mode, the device draws 35mA and 9mA, respectively.

Pricing starts at $1.95 each in 1,000-piece quantities.