LM2674

LM2674 SIMPLE SWITCHER Power Converter High Efficiency 500 mA Step-Down Voltage Regulator September 1998 LM2674 SIMPLE SWITCHER ® Power Converter High Efficiency 500 mA Step-Down Voltage Regulator General Description The LM2674 series of regulators are monolithic integrated circuits built with a LMDMOS process. These regulators provide all the active functions for a step-down (buck) switching regulator, capable of driving a 500 mA load current with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5.0V, 12V, and an adjustable output version. Requiring a minimum number of external components, these regulators are simple to use and include patented internal frequency compensation (Patent Nos. 5,382,918 and 5,514,947) and a fixed frequency oscillator. The LM2674 series operates at a switching frequency of 260 kHz, thus allowing smaller sized filter components than what would be needed with lower frequency switching regulators. Because of its very high efficiency ( > 90%), the copper traces on the printed circuit board are the only heat sinking needed. A family of standard inductors for use with the LM2674 are available from several different manufacturers. This feature greatly simplifies the design of switch-mode power supplies using these advanced ICs. Also included in the datasheet are selector guides for diodes and capacitors designed to work in switch-mode power supplies. Other features include a guaranteed ± 1.5% tolerance o...