The MIC4576 is a series of easy-to-use fixed and adjustable BiCMOS step-down (buck) switch-mode voltage regulators. The 200 kHz MIC4576 duplicates the pinout and function of the 52 kHz LM2576. The higher switching frequency may allow up to a 2:1 reduction in output filter inductor size. The MIC4576 is available in 3.3V, and 5V fixed output versions or a 1.23V to 33V adjustable output version. Both versions are capable of driving a 3A load with excellent line and load regulation. The feedback voltage is guaranteed to ?2% tolerance for adjustable versions, and the output voltage is guaranteed to ?3% for fixed versions, within specified voltages and load conditions. The oscillator frequency is guaranteed to ?10%. In Shutdown mode, the regulator draws less than 200 ?A shutdown current. The regulator performs cycle-by-cycle current limiting and thermal shutdown for protection under fault conditions. This series of simple switch-mode regulators requires a minimum number of external components and can operate using a standard series of inductors. Frequency compensation is provided internally. The MIC4576 is available in TO-220 (T) and TO-263 (U) packages for the industrial temperature range.