LM2671 Datasheet, PDF (1/36 Pages) National Semiconductor (TI) – SIMPLE SWITCHER Power Converter High Efficiency 500mA Step-Down Voltage Regulator with Features

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LM2671
SNVS008L – SEPTEMBER 1998 – REVISED JUNE 2016
LM2671 SIMPLE SWITCHER^® Power Converter High Efficiency 500-mA
Step-Down Voltage Regulator With Features
1 Features
•1 Efficiency up to 96%
• Available in 8-Pin SOIC, PDIP, and WSON
Packages
• Simple and Easy to Design With
• Requires Only 5 External Components
• Uses Readily Available Standard Inductors
• 3.3-V, 5-V, 12-V, and Adjustable Output Versions
• Adjustable Version Output Voltage Range: 1.21 V
to 37 V
• ±1.5% Maximum Output Voltage Tolerance Over
Line and Load Conditions
• Ensured 500-mA Output Load Current
• 0.25-Ω DMOS Output Switch
• Wide Input Voltage Range: 8 V to 40 V
• 260-kHz Fixed Frequency Internal Oscillator
• TTL Shutdown Capability, Low Power Standby
Mode
• Soft-Start and Frequency Synchronization
• Thermal Shutdown and Current-Limit Protection
2 Applications
• Simple High Efficiency (> 90%) Step-Down (Buck)
Regulators
• Efficient Preregulator for Linear Regulators
3 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 500-mA load current with excellent line and
load regulation. These devices are available in fixed
output voltages of 3.3 V, 5 V, 12 V, and an adjustable
output version.
Requiring a minimum number of external
components, these regulators are simple to use and
include patented internal frequency compensation,
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 is required 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
required.
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 data sheet are
selector guides for diodes and capacitors designed to
work in switch-mode power supplies.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
SOIC (8)
4.90 mm × 3.91 mm
LM2674
PDIP (8)
9.81 mm × 6.35 mm
WSON (16)
5.00 mm × 5.00 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Typical Application
For fixed output voltage versions
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.