Two High Power Monolithic Switching Regulators Include
Integrated 6A, 42V or 3.3A, 42V Power Switches,
Built-in Fault Protection and Operation up to 2.5MHz
Matthew Topp and Joshua Moore Power supply designers looking to shrink applications and simplify layout often turn to
monolithic switching regulators. Monolithics simplify power supply layout by including
the power switch on the die—no external FETs or precision sense resistors are needed.
Monolithics can also operate at substantially higher switching frequencies than their
controller-only counterparts, thus reducing the size and number of external passive
components. The benefits of monolithic regulators are clear, but they traditionally have one
major limitation: as the required power level goes up, the likelihood of finding a suitable
monolithic regulator diminishes. Two new high power monolithics, the LT3579 and LT3581,
solve this problem by integrating 6A (42V) and 3.3A (42V) power switches, respectively.
The LT3579 and LT3581 are highly flexible parts and can be configured in
boost, SEPIC, inverting, or flyback configurations. They also offer many unique
performance and fault protection features. When configured as high power
boost converters, these parts can survive
output overloads with only a few additional external components. They can
also be configured to provide hot-plug
and reverse input voltage protection.
In addition, a novel master and slave
power switch design allows high voltage
charge pump circuits to be made with low
power dissipation and few components. …