The LM2675 series of regulators are monolithic integrated DC-DC converter circuits built
with a LMDMOS process. These regulators provide all the active functions for a step-down (buck)
switching regulator, capable of driving a 1-A 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 and a fixed frequency oscillator.
The LM2675 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 LM2675 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 ±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.
