Features
* 150 kHz fixed frequency internal oscillatorn TTL shutdown capability
* Low power standby mode, IQtypically 80 µAn High efficiency
* Uses readily available standard inductors
* Thermal shutdown and current limit protection
Applications
* Simple high-efficiency step-down (buck) regulator
* On-card switching regulators
* Positive to negative converter

Description
The LM2596 series of regulators are monolithic integratedcircuits that provide all the active functions for a step-down(buck) switching regulator, capable of driving a 3A load withexcellent line and load regulation. These devices are avail-able in fixed output voltages of 3.3V, 5V, 12V, and an adjust-able output version.Requiring a minimum number of external components, theseregulators are simple to use and include internal frequencycompensation, and a fixed-frequency oscillator.The LM2596 series operates at a switching frequency of150 kHz thus allowing smaller sized filter components thanwhat would be needed with lower frequency switching regu-lators. Available in a standard 5-lead TO-220 package withseveral different lead bend options, and a 5-lead TO-263surface mount package.A standard series of inductors are available from severaldifferent manufacturers optimized for use with the LM2596 series. This feature greatly simplifies the design ofswitch-mode power supplies.Other features include a guaranteed±4% tolerance on out-put voltage under specified input voltage and output loadconditions, and±15% on the oscillator frequency. Externalshutdown is included, featuring typically 80 µA standby cur-rent. Self protection features include a two stage frequencyreducing current limit for the output switch and an overtemperature shutdown for complete protection under faultconditions