100V Isolated Flyback DC/DC Controller Operates up to 150°C

News Release ⎜ www.linear.com
100V Isolated Flyback DC/DC Controller Operates up to 150°C
MILPITAS, CA – November 3, 2010 – Linear Technology Corporation announces the
LT3748H, a high input voltage isolated flyback DC/DC controller with guaranteed operation for
junction temperatures as high as 150°C. This device significantly simplifies the design of an
isolated DC/DC converter since there is no requirement for an opto-isolator, third winding or
signal transformer for feedback, as the output voltage is sensed from the primary-side flyback
signal. The LT3748 operates over a 5V to 100V input voltage range and drives an external
N-channel power MOSFET, making it well suited for a wide variety of automotive, industrial,
telecom and datacom applications.
The LT3748 operates in a boundary mode, current-mode control switching scheme,
resulting in +/-5% typical regulation over the full line, load and temperature range. Boundary
mode also permits the use of a smaller transformer compared to equivalent continuous
conduction mode designs. The output voltage is easily set by two external resistors and the
transformer turns ratio. Several off-the-shelf transformers identified in the data sheet can be used
for numerous applications. The high level of integration and the use of boundary mode operation
results in a simple, clean application solution to the traditional challenge of isolated power
Additional features include an onboard low drop regulator for IC power, programmable
soft start, undervoltage lockout, adjustable current limit and output voltage temperature
The LT3748H is available in a small MSOP-16 package with 4 pins removed for
additional high voltage pin spacing. The 1,000 piece price starts at $3.71 each. For more
information, visit www.linear.com/3748.
100V Isolated Flyback DC/DC Controller Operates up to 150°C
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Photo Caption: 100V Isolated Flyback Operates up to 150°C
Summary of Features: LT3748H
-40°C to 150°C Guaranteed Junction Temperature Operation
VIN Range from 5V to 100V
No Opto-isolator, Transformer or Third Winding Required for Feedback
Drives External N-Channel Power MOSFET
Current-Mode Control
Boundary Mode Operation
VOUT Set with Two External Resistors
Off-the-Shelf Transformers
Programmable Soft-Start
Programmable Undervoltage Lockout
Output Voltage Temperature Compensation
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.
LT, LTC, LTM, µModule and
are registered trademarks of Linear Technology Corp. All other trademarks are the
property of their respective owners.
Press Contacts:
North America / Worldwide
UK & Nordic
John Hamburger, Director Marketing
Tel 408-432-1900 ext 2419
Alan Timmins
Tel: +44-1-252-629937
Doug Dickinson, Media Relations Manager
408-432-1900 ext 2233