SANTA CLARA, CA., - September 25, 1995 - National Semiconductor today added two
new power converters, designated LM2594 and LM2597, to its Simple Switcher®
family. These 0.5A Simple Switchers in SO-8 surface-mount packages reduce PC power-
supply board space requirements by 50%. High-frequency, 150kHz operation allows the
use of external filtering parts that are smaller and lower-in-profile than the components
normally required with lower-frequency regulators. Both new step-down switching ICs
retain all the popular circuit-design features of National's original line of Simple Switchers.
"The unique Simple Switcher concept allows National's customers to design efficient,
custom power converters in just a half-hour as an alternative to buying an expensive
module," said Al Kelsch, National's analog product marketing manager. "In addition,
users of the LM2594 and LM2597 gain two size advantages. First, both are offered in the
popular SO-8 surface-mount package. Second, the new higher frequency of the two
devices allows usage of the new low-profile, surface-mount inductors and capacitors."
The new space-saver Simple Switcher converters are supported by "Switchers Made
Simple"® design software, which provides customers with a complete design
solution including schematics, component lists and vendor information. Use of standard
inductors or transformers available from National's magnetics partners precludes the need
for any magnetics design. National guarantees system performance for DC/DC converter
applications designed using the components listed in either the company's design software
or data sheets.
Optional features, available only in the LM2597, include a power-on reset indicator with
user- programmable delay; an out-of-regulation flag that indicates below-tolerance
voltages; and a softstart feature to prevent excessive in-rush current. Both new ICs offer
external shutdown and self-protection features such as current limiting and over-
temperature shutdown.
A95004PM
Lit. # 570204-001, 107870-001, 107467-001