¡El LM2574 family is a series of easy to use fixed and adjustable switching voltage regulators. ¡El LM2574 contains all of the active circuitry necessary to construct a stepdown (buck) switching regulator and requires a minimum of external components. ¡El LM2574 is available in 3.3V and 5V fixed output versions, or an adjustable version with an output voltage range of 1.23V to 37V. Output voltage is guaranteed to ±4% for specified input and load conditions. ¡El LM2574 can supply 0.5A while maintaining excellent line and load regulation. ¡El output switch includes cycleby-cycle current limiting, as well as thermal shutdown for full protection under fault conditions. An external shutdown connection selects operating or standby modes. Standby current is less than 200µA. Heat sinks are generally unnecessary due the regulator’s high efficiency. Adequate heat transfer is usually provided by soldering all package pins to a printed circuit board. ¡El LM2574 includes internal frequency compensation and an internal 52kHz fixed frequency oscillator guaranteed to ±10% of the frequency. Circuits constructed around the LM2574 use a standard series of inductors which are available from several different manufacturers.