LM2671M-ADJ Datasheet, PDF (1/31 Pages) Texas Instruments – LM2671 SIMPLE SWITCHER Power Converter High Efficiency 500mA Step-Down Voltage

LM2671
www.ti.com
SNVS008K – SEPTEMBER 1998 – REVISED APRIL 2013
LM2671 SIMPLE SWITCHER^® Power Converter High Efficiency 500mA Step-Down Voltage
Regulator with Features
Check for Samples: LM2671
FEATURES
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•234 Efficiency up to 96%
• Available in SOIC, 8-pin PDIP and WSON
Packages
• Computer Design Software LM267X Made
Simple (version 6.0)
• Simple and Easy to Design With
• Requires Only 5 external Components
• Uses Readily Available Standard Inductors
• 3.3V, 5.0V, 12V, and Adjustable Output
Versions
• Adjustable Version Output Voltage Range:
1.21V to 37V
• ±1.5% Max Output Voltage Tolerance Over
Line and Load Conditions
• Ensured 500mA Output Load Current
• 0.25Ω DMOS Output Switch
• Wide Input Voltage Range: 8V to 40V
• 260 kHz Fixed Frequency Internal Oscillator
• TTL Shutdown Capability, Low Power Standby
Mode
• Soft-Start and Frequency Synchronization
• Thermal Shutdown and Current Limit
Protection
APPLICATIONS
• Simple High Efficiency (>90%) Step-Down
(Buck) Regulator
• Efficient Pre-Regulator for Linear Regulators
DESCRIPTION
The LM2671 series of regulators are monolithic
integrated circuits built with a LMDMOS process.
These regulators provide all the active functions for a
step-down (buck) switching regulator, capable of
driving a 500mA load current with excellent line and
load regulation. These devices are available in fixed
output voltages of 3.3V, 5.0V, 12V, and an adjustable
output version.
Requiring a minimum number of external
components, these regulators are simple to use and
include patented internal frequency compensation
(Patent Nos. 5,382,918 and 5,514,947), fixed
frequency oscillator, external shutdown, soft-start,
and frequency synchronization.
The LM2671 series operates at a switching frequency
of 260 kHz, thus allowing smaller sized filter
components than what would be needed with lower
frequency switching regulators. Because of its very
high efficiency (>90%), the copper traces on the
printed circuit board are the only heat sinking needed.
A family of standard inductors for use with the
LM2671 are available from several different
manufacturers. This feature greatly simplifies the
design of switch-mode power supplies using these
advanced ICs. Also included in the datasheet are
selector guides for diodes and capacitors designed to
work in switch-mode power supplies.
Other features include a ensured ±1.5% tolerance on
output voltage within specified input voltages and
output load conditions, and ±10% on the oscillator
frequency. External shutdown is included, featuring
typically 50 μA stand-by current. The output switch
includes current limiting, as well as thermal shutdown
for full protection under fault conditions.
To simplify the LM2671 buck regulator design
procedure, there exists computer design software,
LM267X Made Simple (version 6.0).
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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
SIMPLE SWITCHER, WEBENCH are registered trademarks of Texas Instruments.
2
Windows is a registered trademark of Microsoft Corporation.
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All other trademarks are the property of their respective owners.
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PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 1998–2013, Texas Instruments Incorporated