National Semiconductor LM2597 Manuals

LM2597/LM2597HV SIMPLE SWITCHER® Power Converter 150 kHz 0.5A Step-Down Voltage Regulator is a switching power supply IC with adjustable output voltage and can be equipped with different external components.

LM2597/LM2597HV is a monolithic integrated circuit that provides all the active functions for a step-down (buck) switching regulator. It is capable of driving a 0.5A load with excellent line and load regulation, and supports 3.3V, 5V, 12V fixed output and adjustable output. It also features internal frequency compensation, improved line and load specifications, fixed-frequency oscillator, Shutdown /Soft-start, error flag delay and error flag output.

The LM2597/LM2597HV series are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching regulator, capable of driving a 0.5A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5V, 12V, and an adjustable output version, and are packaged in an 8-lead DIP and an 8-lead surface mount package. This series of switching regulators is similar to the LM2594 series, with additional supervisory and performance features added. Requiring a minimum number of external components, these regulators are simple to use and include internal frequency compensation†, improved line and load specifications, fixed-frequency oscillator, Shutdown /Soft-start, error flag delay and error flag output. The LM2597/LM2597HV 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 cop- per traces on the printed circuit board are normally the only heat sinking needed. A standard series of inductors (both through hole and sur- face mount types) are available from several different manu- facturers optimized for use with the LM2597/LM2597HV se- ries. This feature greatly simplifies the design of switch-