The LM2671 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 3.3 V, 5 V, 12 V, and an adjustable output version.
●Requiring a minimum number of external components, these regulators are simple to use and include patented internal frequency compensation, fixed frequency oscillator, external shutdown, soft start, and frequency synchronization.
●The LM2671 series operates at a switching frequency of 260 kHz, thus allowing smaller sized filter components than what is required 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 required.
●A family of standard inductors for use with the LM2671 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 data sheet are selector guides for diodes and capacitors designed to work in switch-mode power supplies.
●Other features include a ensured ±1.5% tolerance on output voltage within specified input voltages and output load conditions, and ±10% on the oscillator frequency. External shutdown is included, featuring typically 50-µA standby current. The output switch includes current limiting, as well as thermal shutdown for full protection under fault conditions.
