Converter IC Steps Down To 1.8V

The MAX1730 is a regulated step-down charge-pump dc-to-dc converter that generates a fixed 1.8V, 1.9V or adjustable output from a 2.7V to 5.5V input. The device does not need an inductor and uses fractional conversion techniques to create a dc-to-dc converter with efficiency much greater than a linear regulator. A typical application generates a 1.8V core logic supply from a Li-Ion battery of 3.6V. Efficiency is close to 80% for long battery life. The device operates at up to 2 MHz permitting the use of 0.22 µF flying capacitors. Quiescent supply current is 75 µA, and in the shutdown mode with the output disconnected from the input the IC uses 1 µA. Furthermore, a proprietary soft-start circuit prevents excessive inrush current at startup. Price starts at $1.45 each/1000 in 10-pin µMAX or 8-pin SO packages.