36V, 1.5A Buck and 1.5A Boost 2MHz Step-Down DC/DC Converters & LDO Controller in 4mm x 4mm QFN

News Release ⎜ www.linear.com
36V, 1.5A Buck and 1.5A Boost 2MHz Step-Down DC/DC Converters & LDO
Controller in 4mm x 4mm QFN
MILPITAS, CA – December 3, 2008 – Linear Technology Corporation announces the LT3570, a
36V, 1.5A(ISW) buck and boost regulator combined with a linear controller packaged in a 4mm x
4mm QFN or TSSOP-20E. The LT3570 operates from a VIN range of 2.5V to 36V (40VMAX),
making it ideal for the load dump and cold-crank conditions commonly found in automotive
applications. Independent input pins can be tied together to run from a single input or can be run
from independent input rails. The buck regulator can deliver up to 1A of continuous output
current at voltages as low as 0.8V whereas the boost converter can deliver output voltages as
high as 38V.
The LDO controller combined with an external NPN transistor can be run from the output
of the buck regulator for maximum efficiency or via an independent input pin for design
flexibility, either way providing low noise operation. Switching frequency is user programmable
from 500kHz to 2MHz, enabling the designer to optimize efficiency while avoiding critical
noise-sensitive frequency bands and is synchronizable from 650kHz to 2.5MHz. The
combination of its 4mm x 4mm QFN package (or thermally enhanced TSSOP-20) and high
switching frequency, which keeps external capacitors and the inductor small, provides a very
compact, thermally efficient footprint.
Both the LT3570’s buck and boost switchers utilize high efficiency 1.5A, 240mVCESAT
switches, with the necessary oscillator, control, logic circuitry and LDO controller integrated into
a single die. Special design techniques enable efficiencies of up to 88% over a wide input voltage
range while current mode topology enables fast transient response and excellent loop stability.
Other features include independent soft-start capability for each channel and thermal shutdown.
The LT3570EUF is packaged in a 4mm x 4mm QFN and pricing starts at $2.95 each, for
1,000-piece quantities. The LT3570EFE is packaged in a thermally enhanced TSSOP-20 and
pricing starts at $3.05 each, for 1,000-piece quantities. The LT3570IUF and LT3570IFE are
36V, 1.5A Buck and 1.5A Boost 2MHz Step-Down DC/DC
Converters & LDO Controller in 4mm x 4mm QFN
page 2
tested and guaranteed to operate from a -40°C to 125°C operating junction temperature and are
priced at $3.39 each and $3.51each, respectively for 1,000-piece quantities. All versions are
available from stock.
Photo Caption: 36V, 1.5A (ISW), 2MHz Buck & Boost Switching Regulator with LDO Controller
Summary of Features: LT3570
2.5V to 36V Input Voltage Range
Programmable Switching Frequency from 500kHz to 2MHz
Synchronizable Up to 2.5MHz
Buck VOUT(MIN) = 0.8V
Boost : VOUT(MAX) = 38V
Independent Soft-Start for Each Converter
Separate VIN Supplies for Each Converter
Duty Cycle Range: 0% to 90% at 1MHz
Available in Thermally Enhanced 24-Lead (4mm × 4mm) QFN & 20-Lead TSSOP Packages
About Linear Technology
Linear Technology Corporation, a manufacturer of high performance linear integrated circuits,
was founded in 1981, became a public company in 1986 and joined the S&P 500 index of major
public companies in 2000. Linear Technology products include high performance amplifiers,
comparators, voltage references, monolithic filters, linear regulators, DC-DC converters, battery
chargers, data converters, communications interface circuits, RF signal conditioning circuits,
uModule™ products, and many other analog functions. Applications for Linear Technology’s
high performance circuits include telecommunications, cellular telephones, networking products
such as optical switches, notebook and desktop computers, computer peripherals,
video/multimedia, industrial instrumentation, security monitoring devices, high-end consumer
products such as digital cameras and MP3 players, complex medical devices, automotive
electronics, factory automation, process control, and military and space systems. For more
information, visit www.linear.com.
LT, LTC, LTM and
are registered trademarks and uModule is a trademark of Linear Technology Corp. All other
trademarks are the property of their respective owners.
Press Contacts:
John Hamburger, Director Marketing Communications
[email protected]
Tel: 408-432-1900 ext 2419
Doug Dickinson, Media Relations Manager
[email protected]
Tel: 408-432-1900 ext 2233