LM5576,pdf datasheet (3A Step-

The LM5576 is an easy to use SIMPLE SWITCHER® buck
regulator which allows design engineers to design and optimize
a robust power supply using a minimum set of components.
Operating with an input voltage range of 6 - 75V, the
LM5576 delivers 3A of continuous output current with an integrated
170mΩ N-Channel MOSFET. The regulator utilizes
an Emulated Current Mode architecture which provides inherent
line regulation, tight load transient response, and ease
of loop compensation without the usual limitation of low-duty
cycles associated with current mode regulators. The operating
frequency is adjustable from 50kHz to 500kHz to allow
optimization of size and efficiency. To reduce EMI, a frequency
synchronization pin allows multiple IC’s from the
LM(2)557x family to self-synchronize or to synchronize to an
external clock. The LM5576 guarantees robustness with cycle-
by-cycle current limit, short-circuit protection, thermal
shut-down, and remote shut-down. The device is available in
a power enhanced TSSOP-20 package featuring an exposed
die attach pad for thermal dissipation. The LM5576 is supported
by the full suite of WEBENCH® On-Line design tools.