Boost Dc-Dc Converters Offer High Efficiency

High-efficiency synchronous rectification is a key feature in the SP6642 and SP6643 dc-dc switching boost converters. One low-profile, 100-µH coil and one filter capacitor are the only external components users must add to these devices to generate a 3.3V regulated-output voltage.With only a 0.85V battery input, the converters are guaranteed to start up and maintain a regulated voltage output which is either preset for 3.3V or adjustable from 2V to 5V. Once the device has started, the output voltage can typically be maintained down to a 0.2V battery input voltage. The SP6642 also features a low-power shutdown mode in which the device draws less than 1 µA. In the SP6643, the shutdown feature is replaced by a battery-low indicator. Both come in 8-pin µSOIC packages and are suited for single alkaline-cell applications.