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

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	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 260000 Hz

Frequency Max 260000 Hz

Efficiency (peak) 90 %

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 260000 Hz

Frequency Max 260000 Hz

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 Feedfoward

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 260000 Hz

Regulator Family SIMPLE SWITCHER

View Using Catalog

Typical Performance

click for larger image

WEBENCH Live Simulation!

LM2671 WEBENCH® Custom Design/Analyze/Build It/Test It
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

LM25574	Wider Input Voltage Range (6 To 42V) And Higher Switching Frequency (Up To 1MHz)
LM2597HV	4.5V To 60V Input Voltage Range
LM2619	Synchronous Rectification For Higher Efficiency, Higher Switching Frequency, Smaller Package
LM2672	1A Output Current
LM5007	80V 0.5A Switching Regulator
LM5574	Wider 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 Kbytes	Date
LM2671 SIMPLE SWITCHER Power Converter High Efficiency 500mA Step-Down Voltage Regulator with Features	620 Kbytes	5-Apr-07	View Online	Download	Receive via Email
LM2671 SIMPLE SWITCHER Power Converter High Efficiency 500mA Step-Down Voltage Regulator with Features (Japanese)	1099 Kbytes

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

Package Availability, Models, Samples & Pricing

Part Number

Package

Factory Lead Time

Models

Samples &
Electronic
Orders

Budgetary Pricing

Std
Pack
Size

Package
Marking
Format

Type

Pins

Spec.

MSL
Rating

Peak
Reflow

RoHS
Report

CAD
Symbols

Qty

Qty

$US each

LM2671LD-12

16

NOPB

3

260

Lifetime buy

N/A

1K+

$1.38

reel
of
1000

NS
UZXYTT
S0005B

12 weeks

2000

LM2671LD-3.3

16

NOPB

3

260

Lifetime buy

N/A

1K+

$1.38

reel
of
1000

NS
UZXYTT
S0006B

6 weeks

2000

LM2671LD-5.0

16

NOPB

3

260

Lifetime buy

N/A

1K+

$1.38

reel
of
1000

NS
UZXYTT
S0007B

6 weeks

N/A

LM2671LD-ADJ

16

STD

NOPB

1

3

235

260

Full production

N/A

1K+

$1.38

reel
of
1000

NS
UZXYTT
S0008B

6 weeks

7500

LM2671LDX-12

16

Lifetime buy

N/A

1K+

$1.38

reel
of
4500

NS
UZXYTT
S0005B

16 weeks

N/A

LM2671LDX-3.3

16

Lifetime buy

N/A

1K+

$1.38

reel
of
4500

NS
UZXYTT
S0006B

16 weeks

N/A

LM2671LDX-5.0

16

Lifetime buy

N/A

1K+

$1.38

reel
of
4500

NS
UZXYTT
S0007B

16 weeks

N/A

LM2671LDX-ADJ

16

Lifetime buy

N/A

1K+

$1.38

reel
of
4500

NS
UZXYTT
S0008B

16 weeks

N/A

LM2671M-12

8

STD

NOPB

1

1

235

260

Full production

N/A

Samples

1K+

$1.38

rail
of
95

NSZXTT
2671
M-12

6 weeks

500

LM2671M-3.3

8

STD

NOPB

1

1

235

260

Full production

N/A

Samples

1K+

$1.38

rail
of
95

NSZXTT
2671
M3.3

12 weeks

2000

LM2671M-5.0

8

STD

NOPB

1

1

235

260

Full production

N/A

Samples

1K+

$1.38

rail
of
95

NSZXTT
2671
M5.0

8 weeks

1000

LM2671M-ADJ

8

STD

NOPB

1

1

235

260

Full production

N/A

Samples

1K+

$1.38

rail
of
95

NSZXTT
2671
MADJ

8 weeks

1000

LM2671MX-12

8

NOPB

1

260

Full production

N/A

1K+

$1.38

reel
of
2500

NSZXTT
2671
M-12

8 weeks

3000

LM2671MX-3.3

8

NOPB

1

260

Full production

N/A

1K+

$1.38

reel
of
2500

NSZXTT
2671
M3.3

12 weeks

7500

LM2671MX-5.0

8

STD

NOPB

1

1

235

260

Full production

N/A

1K+

$1.38

reel
of
2500

NSZXTT
2671
M5.0

6 weeks

7500

LM2671MX-ADJ

8

STD

NOPB

1

1

235

260

Full production

N/A

1K+

$1.38

reel
of
2500

NSZXTT
2671
MADJ

6 weeks

7500

LM2671N-12

8

NOPB

1

NA

Full production

N/A

Samples

1K+

$1.38

rail
of
40

NSUZXYTT
LM2671
N-12

8 weeks

10

LM2671N-3.3

8

NOPB

1

NA

Full production

N/A

Samples

1K+

$1.38

rail
of
40

NSUZXYTT
LM2671
N-3.3

16 weeks

500

LM2671N-5.0

8

STD

NOPB

1

1

NA

NA

Full production

N/A

1K+

$1.38

rail
of
40

NSUZXYTT
LM2671
N-5.0

6 weeks

1000

LM2671N-ADJ

8

STD

NOPB

1

1

NA

NA

Full production

N/A

Samples

1K+

$1.38

rail
of
40

NSUZXYTT
LM2671
N-ADJ

8 weeks

1000

Obsolete Parts

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM2671LD-12	NONE	NONE	11/16/2008
LM2671LD-3.3	NONE	NONE	11/16/2008
LM2671LD-5.0	NONE	NONE	11/16/2008
LM2671LDX-12	NONE	NONE	11/16/2008
LM2671LDX-3.3	NONE	NONE	11/16/2008
LM2671LDX-5.0	NONE	NONE	11/16/2008
LM2671LDX-ADJ	NONE	NONE	11/16/2008

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	Early Failure Rate - Rejects	Sample Size (EFR)	PPM *	Rel. Rejects	Device Hours	Long Term Failure Rates (FITS)	MTTF
LM2671LD-12	LMDMOS	0	12670	0	0	1210000	3	343340803
LM2671LD-3.3	LMDMOS	0	12670	0	0	1210000	3	343340803
LM2671LD-5.0	LMDMOS	0	12670	0	0	1210000	3	343340803
LM2671LD-ADJ	LMDMOS	0	12670	0	0	1210000	3	343340803
LM2671LDX-12	LMDMOS	0	12670	0	0	1210000	3	343340803
LM2671LDX-3.3	LMDMOS	0	12670	0	0	1210000	3	343340803
LM2671LDX-5.0	LMDMOS	0	12670	0	0	1210000	3	343340803
LM2671LDX-ADJ	LMDMOS	0	12670	0	0	1210000	3	343340803
LM2671M-12	LMDMOS	0	12670	0	0	1210000	3	343340803
LM2671M-3.3	LMDMOS	0	12670	0	0	1210000	3	343340803
LM2671M-5.0	LMDMOS	0	12670	0	0	1210000	3	343340803
LM2671M-ADJ	LMDMOS	0	12670	0	0	1210000	3	343340803
LM2671MX-12	LMDMOS	0	12670	0	0	1210000	3	343340803
LM2671MX-3.3	LMDMOS	0	12670	0	0	1210000	3	343340803
LM2671MX-5.0	LMDMOS	0	12670	0	0	1210000	3	343340803
LM2671MX-ADJ	LMDMOS	0	12670	0	0	1210000	3	343340803
LM2671N-12	LMDMOS	0	12670	0	0	1210000	3	343340803
LM2671N-3.3	LMDMOS	0	12670	0	0	1210000	3	343340803
LM2671N-5.0	LMDMOS	0	12670	0	0	1210000	3	343340803
LM2671N-ADJ	LMDMOS	0	12670	0	0	1210000	3	343340803

For more information on Reliability Metrics, please click here.

Design Tools

Title	Size in Kbytes	Date
SimpleSwitcher® DC-DC Converters Design Software	12 Kbytes	11-Jan-2008	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

Title	Size in Kbytes	Date
AN-1819: Application Note 1819 LM5118 Evaluation Board	390 Kbytes	30-Apr-08	View Online	Download	Receive via Email
AN-1061: Application Note 1061 Power Conversion in Line-Powered Equipment	188 Kbytes	1-Oct-02	View Online	Download	Receive via Email
AN-1061 (Japanese): Application Note 1061 Power Conversion in Line-Powered Equipment	215 Kbytes

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

[Information as of 9-May-2008]

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