The LM2574xx series of regulators are monolithic integrated circuits that provide all the
active functions for a step-down (buck) switching regulator, capable of driving a 0.5-A load with
excellent line and load regulation. These devices are available in fixed output voltages of 3.3 V,
5 V, 12 V, 15 V, and an adjustable output version.
Requiring a minimum number of external components, these regulators are simple to use and
include internal frequency compensation and a fixed-frequency oscillator.
The LM2574xx series offers a high-efficiency replacement for popular three-terminal
linear regulators. Because of its high efficiency, the copper traces on the printed-circuit board
(PCB) are normally the only heat sinking needed.
A standard series of inductors optimized for use with the LM2574 are available from
several different manufacturers. This feature greatly simplifies the design of switch-mode power
Other features include a specified ±4% tolerance on output voltage within specified input
voltages and output load conditions, and ±10% on the oscillator frequency. External shutdown is
included, featuring 50-µA (typical) standby current. The output switch includes cycle-by-cycle
current limiting, as well as thermal shutdown for full protection under fault conditions.
The TPS560430 is
a newer generation buck converter, being functionally equivalent to LM2574. It offers reduced BOM
cost, increased efficiency, and reduced solution size. See the Device Comparison Table to compare
WEBENCH Design with TPS560430.