LM2671 - SIMPLE SWITCHER Power Converter High Efficiency 500mA Step-Down Voltage Regulator with Features

Datasheet Packaging Samples & Pricing Reliability Design Tools Reference Designs Application Notes Knowledge Base

Features
Efficiency up to 96%
Available in SO-8, 8-pin DIP and LLP 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
Guaranteed 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

General Description


The LM2671 series of regulators are monolithic integrated circuits built with a LMDMOS process. More...


Applications


Simple High Efficiency (>90%) Step-Down (Buck) Regulator
Efficient Pre-Regulator for Linear Regulators
  Typical Application
click for larger image


Parametric Table     expand
Parametric Table    collapse
Output Current 500 mA
Input Min Voltage 6.5 Volt
Input Max Voltage 40 Volt
Output Min 1.23 Volt
Output Max 37 Volt
Frequency Min 260 kHz
Frequency Max 260 kHz
Output Current 500 mA
Input Min Voltage 6.5 Volt
Input Max Voltage 40 Volt
Output Min 1.23 Volt
Output Max 37 Volt
Frequency Min 260 kHz
Frequency Max 260 kHz
Efficiency (peak) 90 %
On/Off Pin Yes
Error Flag No
SoftStart Yes
Sync Pin Yes
Flyback No
RegType Switching Regulator
Temperature Min -40 deg C
Temperature Max 125 deg C
Adjustable Output Yes
Adj Switch Frequency No
PWM Mode Voltage with Vin Feedforward
Topology Buck
Special Features Internal Type 3 compensation, 1.5% output voltage accuracy, SIMPLE SWITCHER regulator
Step-Down Yes
Multiple Output Capability No
Output Power Undefined Watt
Output Voltage Undefined Volt
Output Range 1.23V to 37V
Switching Frequency 260 kHz
Regulator Family SIMPLE SWITCHER
AEC Q-100 Automotive Grade Undefined
Synchronous Rectification No
View Using Catalog


Typical Performance


click for larger image


  WEBENCH Live Simulation!
WEBENCH® Designer

LM2671

 
6.50 <=
V in Lower
 V
 
<=
V in Upper
 V
 
<= 40.00
V out 1.21 <=  V <= 40.00
I out    A <= 0.50
Ambient Temperature  °C <= 100


What are WEBENCH® tools?


Also Recommended
LM22671Wider Input Voltage Range (4.5 To 42V), 500 KHz Or Adjustable Switching Frequency Up To 1MHz
LM25574Fast Transient Response And Higher Switching Frequency (Up To 1MHz)
LM5574Wider Input Voltage Range (6 To 75V) And Higher Switching Frequency (Up To 500kHz)

Additional Resources


Design Tools (see below)

Application Notes (see below)


See Layout Guidelines

Block Diagram


click for larger image



Datasheet
RoHS Compliance Information Size in KbytesDate Click link below to Download
LM2671 SIMPLE SWITCHER Power Converter High Efficiency 500mA Step-Down Voltage Regulator with Features 620 Kbytes 5-Apr-07 Download
LM2671 SIMPLE SWITCHER Power Converter High Efficiency 500mA Step-Down Voltage Regulator with Features (Japanese)
1113 Kbytes   Download

If you have trouble printing or viewing PDF file(s), see Printing Problems.


Package Availability, Models, Samples & Pricing
Part NumberPackageFactory Lead TimeModelsSamples &
Electronic
Orders
Budgetary PricingStd
Pack
Size
Package
Marking
Format
TypePinsSpec.MSL
Rating
Peak
Reflow
RoHS
Report
CAD
Symbols
WeeksQtyQty$US each
LM2671LD-12LLP16RoHS Download ObsoleteN/A
 
Buy Now
1K+$1.49reel
of
1000
NS
UZXYTT
S0005B
16 weeksN/A
LM2671LD-5.0LLP16STD1235RoHS Download ObsoleteN/A
 
Buy Now
1K+$1.49reel
of
1000
NS
UZXYTT
S0007B
12 weeks2000
LM2671LD-ADJLLP16STD
NOPB
1
3
235
260
RoHS Download Full productionN/A
 
Buy Now
1K+$1.38reel
of
1000
NS
UZXYTT
S0008B
6 weeks2000
LM2671M-12SOIC NARROW8STD
NOPB
1
1
235
260
RoHS Download Full productionN/A
Samples
Buy Now
1K+$1.38rail
of
95
NSZXTT
2671
M-12
6 weeks1000
LM2671M-3.3SOIC NARROW8STD
NOPB
1
1
235
260
RoHS Download Full productionN/A
Samples
Buy Now
1K+$1.38rail
of
95
NSZXTT
2671
M3.3
6 weeks500
LM2671M-5.0SOIC NARROW8STD
NOPB
1
1
235
260
RoHS Download Full productionN/A
Samples
Buy Now
1K+$1.38rail
of
95
NSZXTT
2671
M5.0
6 weeks500
LM2671M-ADJSOIC NARROW8STD
NOPB
1
1
235
260
RoHS Download Full productionN/A
Samples
Buy Now
1K+$1.38rail
of
95
NSZXTT
2671
MADJ
12 weeks500
LM2671MX-12SOIC NARROW8NOPB1260RoHS Download Full productionN/A
 
Buy Now
1K+$1.38reel
of
2500
NSZXTT
2671
M-12
6 weeks5000
LM2671MX-3.3SOIC NARROW8NOPB1260RoHS Download Full productionN/A
 
Buy Now
1K+$1.38reel
of
2500
NSZXTT
2671
M3.3
6 weeks10000
LM2671MX-5.0SOIC NARROW8STD
NOPB
1
1
235
260
RoHS Download Full productionN/A
 
Buy Now
1K+$1.38reel
of
2500
NSZXTT
2671
M5.0
6 weeks5000
LM2671MX-ADJSOIC NARROW8STD
NOPB
1
1
235
260
RoHS Download Full productionN/A
 
Buy Now
1K+$1.38reel
of
2500
NSZXTT
2671
MADJ
6 weeks3000
LM2671N-12MDIP8NOPB1NARoHS Download Full productionN/A
Samples
Buy Now
1K+$1.38rail
of
40
NSUZXYTT
LM2671
N-12
6 weeksN/A
LM2671N-3.3MDIP8NOPB1NARoHS Download Full productionN/A
Samples
Buy Now
1K+$1.38rail
of
40
NSUZXYTT
LM2671
N-3.3
6 weeks500
LM2671N-5.0MDIP8STD
NOPB
1
1
NA
NA
RoHS Download Full productionN/A
 
Buy Now
1K+$1.38rail
of
40
NSUZXYTT
LM2671
N-5.0
6 weeks500
LM2671N-ADJMDIP8STD
NOPB
1
1
NA
NA
RoHS Download Full productionN/A
Samples
Buy Now
1K+$1.38rail
of
40
NSUZXYTT
LM2671
N-ADJ
6 weeks2000

Obsolete Versions

Obsolete PartAlternate Part or SupplierSourceLast Time Buy Date
LM2671LD-12
NONE
NATIONAL SEMICONDUCTOR
16 Nov 2008
LM2671LD-3.3
NONE
NATIONAL SEMICONDUCTOR
16 Nov 2008
LM2671LD-5.0
NONE
NATIONAL SEMICONDUCTOR
16 Nov 2008
LM2671LDX-12
NONE
NATIONAL SEMICONDUCTOR
16 Nov 2008
LM2671LDX-3.3
NONE
NATIONAL SEMICONDUCTOR
16 Nov 2008
LM2671LDX-5.0
NONE
NATIONAL SEMICONDUCTOR
16 Nov 2008
LM2671LDX-ADJ
NONE
NATIONAL SEMICONDUCTOR
16 Nov 2008

General 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 guaranteed ±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).

Reliability Metrics


Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
LM2671LD-12LMDMOS0168100022000002624256007
LM2671LD-5.0LMDMOS0168100022000002624256007
LM2671LD-ADJLMDMOS0168100022000002624256007
LM2671M-12LMDMOS0168100022000002624256007
LM2671M-3.3LMDMOS0168100022000002624256007
LM2671M-5.0LMDMOS0168100022000002624256007
LM2671M-ADJLMDMOS0168100022000002624256007
LM2671MX-12LMDMOS0168100022000002624256007
LM2671MX-3.3LMDMOS0168100022000002624256007
LM2671MX-5.0LMDMOS0168100022000002624256007
LM2671MX-ADJLMDMOS0168100022000002624256007
LM2671N-12LMDMOS0168100022000002624256007
LM2671N-3.3LMDMOS0168100022000002624256007
LM2671N-5.0LMDMOS0168100022000002624256007
LM2671N-ADJLMDMOS0168100022000002624256007

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

For more information on Reliability Metrics, please click here.


Design Tools


TitleSize in Kbytes Date Click link below to Download    
SimpleSwitcher® DC-DC Converters Design Software     View    
Power Reference Design Library 0 Kbytes 28-Mar-2006 View    

If you have trouble printing or viewing PDF file(s), see Printing Problems.


Reference Designs
LM2671 Reference Design - Buck Converter for Point Of Load Applications: 24V Input, 3.3V @ 0.5A Output

Application Notes


TitleSize in Kbytes Date Click link below to Download
AN-1061: Application Note 1061 Power Conversion in Line-Powered Equipment 162 Kbytes 1-Oct-02 Download
AN-1061 (Japanese): Application Note 1061 Power Conversion in Line-Powered Equipment
215 Kbytes   Download

If you have trouble printing or viewing PDF file(s), see Printing Problems.

More Application Notes


TitleSize in Kbytes Date Click link below to Download
AN-1135: Application Note 1135 LM267X 3A, 5A Evaluation Boards 1208 Kbytes 10-May-04 Download
AN-1157: Application Note 1157 Positive to Negative Buck‐Boost Converter Using LM267X SIMPLE SWITCHER® Regulators 189 Kbytes 1-May-04 Download
AN-1157 (Japanese): Application Note 1157 Positive to Negative Buck‐Boost Converter Using LM267X SIMPLE SWITCHER® Regulators
193 Kbytes   Download
AN-1157 (Chinese): Application Note 1157 Positive to Negative Buck‐Boost Converter Using LM267X SIMPLE SWITCHER® Regulators
307 Kbytes  
AN-1120: Application Note 1120 LM2675-5.0EVAL 1 Amp Step-Down High-Efficiency SIMPLE SWITCHER Evaluation Board 44 Kbytes 4-Oct-04 Download
AN-1229: Application Note 1229 SIMPLE SWITCHER PCB Layout Guidelines 229 Kbytes 1-May-04 Download
AN-1229 (Japanese): Application Note 1229 SIMPLE SWITCHER PCB Layout Guidelines
304 Kbytes   Download
AN-1229 (Chinese): Application Note 1229 SIMPLE SWITCHER PCB Layout Guidelines
668 Kbytes  

If you have trouble printing or viewing PDF file(s), see Printing Problems.

[Information as of 3-Jul-2009]