The LM2594xx series of regulators are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching regulator, capable of driving a 0.5-A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3 V, 5 V, 12 V, and an adjustable output version, and are packaged in a 8-pin PDIP and a 8pin surface-mount SOIC package. Requiring a minimum number of external components, these regulators are simple to use and feature internal frequency compensation, a fixedfrequency oscillator, and improved line and load regulation specifications. The LM2594xx series operates at a switching frequency of 150-kHz, thus allowing smaller-sized filter components than what would be needed with lower-frequency switching regulators. Because of its high efficiency, the copper traces on the printedcircuit board are normally the only heat sinking needed.