lm2576 pdf

The LM2576 series of regulators are monolithic integrated circuits
ideally suited for easy and convenient design of a step−down
switching regulator (buck converter). All circuits of this series are
capable of driving a 3.0 A load with excellent line and load regulation.
These devices are available in fixed output voltages of 3.3 V, 5.0 V,
12 V, 15 V, and an adjustable output version.
These regulators were designed to minimize the number of external
components to simplify the power supply design. Standard series of
inductors optimized for use with the LM2576 are offered by several
different inductor manufacturers.
Since the LM2576 converter is a switch−mode power supply, its
efficiency is significantly higher in comparison with popular
three−terminal linear regulators, especially with higher input voltages.
In many cases, the power dissipated is so low that no heatsink is
required or its size could be reduced dramatically.
A standard series of inductors optimized for use with the LM2576
are available from several different manufacturers. This feature
greatly simplifies the design of switch−mode power supplies.
The LM2576 features include a guaranteed ±4% tolerance on output
voltage within specified input voltages and output load conditions, and
±10% on the oscillator frequency (±2% over 0°C to 125°C). External
shutdown is included, featuring 80 A (typical) standby current. The
output switch includes cycle−by−cycle current limiting, as well as
thermal shutdown for full protection under fault conditions.