GENERAL DESCRIPTION 

The LM2596 series of regulators are monolithic  integrated circuits that provide all the active functions for a  step-down (buck) switching regulator, capable of driving 3A  load with excellent line and  load regulation. These devices are available in fixed output  voltages of 3.3V, 5V, 12V, 15V and an adjustable output  versions. 

Requiring a minimum number of external components,  these regulators are simple to use and include internal  frequency compensation, and a fixed-frequency oscillator. 

The LM2596 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. Available in a standard 5-lead TO-263, surface mount packages.

Some features include a guaranteed  4% tolerance on  output voltage under specified input voltage and output load  conditions, and 15% on the oscillator frequency. External  shutdown is included, featuring typically 50A standby current.  The output switch includes cycle-by-cycle current limiting, as  well as thermal shutdown for full protection under fault  conditions. The oscillator frequency reduces in the event of an  output short or an overload which causes the regulated output  voltage to drop approximately 40% from the nominal output  voltage. 

FEATURES 

 3.3V, 5V, 12V, 15V, and adjustable output versions 

 Adjustable version output voltage range, 1.23V to 37V  3% max over line and load  conditions 

 Guaranteed 3A output current 

 Wide input voltage range 

 Requires only 4 external components 

 150 kHz fixed frequency oscillator 

 TTL shutdown capability, low power standby mode 

 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