Switch-mode voltage regulators LM2575/LM2577 (National Semiconductor)

The recently introduced LM2575 and LM2577 switch-mode voltage regulators in the Simple Switcher series from National Semiconductor have a wide voltage range, and are remarkably easy to get going with only a handful of external components. The devices in the LM2575 series are step-down regulators, and those in the LM2577 series step-up regulators. Offering an efficiency of over 80%, these ICs are a good alternative to the ubiquitous 1-A regulators in the 78xx series.