1 Features
• Newer products available:
– LMR51430 4.5 to 36-V, 3-A, 500-kHz and 1.1-
MHz synchronous converter
– LM76003 3.5 to 60-V, 3.5-A, 300-kHz to 2.2-
MHz synchronous converter
• For faster time to market:
– TLVM13630 3 to 36-V, 3-A, 200-kHz to 2.2-MHz
power module
• 3.3-V, 5-V, 12-V, 15-V, and adjustable output
versions
• Adjustable version output voltage range,1.23 V to
37 V (57 V for HV version) ±4% maximum over line
and load conditions
• Specified 3-A output current
• Wide input voltage range: 40 V Up to 60 V for HV
version
• Requires only four external components
• 52-kHz fixed-frequency internal oscillator
• TTL-shutdown capability, low-power standby mode
• High efficiency
• Uses readily available standard inductors
• Create a custom design using the LMR33630 or
LM76003 with the WEBENCH® Power Designer

2 Applications
• Motor drives
• Merchant network and server PSU
• Appliances
• Test and measurement equipment

3 Description
The LM2576 series of regulators are monolithic
integrated circuits that provide all the active functions
for a step-down (buck) switching regulator, capable
of driving 3-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 fault protection and a fixed-frequency
oscillator.
The LM2576 series offers a high-efficiency
replacement for popular three-terminal linear
regulators. It substantially reduces the size of the heat
sink, and in some cases no heat sink is required.
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.
Other features include a ±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 LM76003 requires very few external components
and has a pinout designed for simple, optimum PCB
layout for EMI and thermal performance. See the
device comparison table to compare specs.