DC/DC Converter Delivers 500 mA Without Inductors

Offered in a 10-lead MSOP package, the LTC3251 step-down dc/dc converter delivers up to 500 mA of continuously without the aid of inductors. Operating with an input voltage range of 2.7V to 5.5V makes it suitable for use in single-cell Li-Ion or multi-cell NiMH and alkaline battery applications. Output voltage is programmable via a resistor from 0.9V to 1.6V. The LTC3251 is also said to be the first such device to employ a two-phase, spread-spectrum architecture, which promises low noise on inputs and outputs. The switching frequency randomly cycles within the range of 1 to 1.6 MHz to minimize the effects of harmonic switching spikes. Other features include four operating modes: continuous spread spectrum; spread spectrum with burst mode; super burst mode; and shutdown mode. Operating current is 35 µA in burst mode and 9 µA in super burst mode. Pricing starts at $1.95 each/1,000. LINEAR TECHNOLOGY CORP., Milpitas, CA. (800) 454-6327.