LM2576 - SIMPLE SWITCHER® 3A Step-Down Voltage Regulator

LM2576 - SIMPLE SWITCHER® 3A Step-Down Voltage Regulator

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

Features

•	3.3V, 5V, 12V, 15V, and adjustable output versions
•	Adjustable version output voltage range, 1.23V to 37V (57V for HV version) ±4% max over line and load conditions
•	Guaranteed 3A output current
•	Wide input voltage range, 40V up to 60V for HV version
•	Requires only 4 external components
•	52 kHz fixed frequency internal oscillator
•	TTL shutdown capability, low power standby mode
•	High efficiency
•	Uses readily available standard inductors
•	Thermal shutdown and current limit protection
•	P+ Product Enhancement tested

General Description

The LM2576 series of regulators are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching regulator, capable of driving 3A load with excellent line and load regulation. More...

Applications

•	Simple high-efficiency step-down (buck) regulator
•	Efficient pre-regulator for linear regulators
•	On-card switching regulators
•	Positive to negative converter (Buck-Boost)

Parameters Values

Output Current 3000 mA

Input Min Voltage 4 Volt

Input Max Voltage 40 Volt

Output Min 3.3, 1.23, 12, 15, 5 Volt

Output Max 3.3, 37, 12, 15, 5 Volt

Frequency Min 52 kHz

Frequency Max 52 kHz

Efficiency (peak) 77, 88, 75 %

On/Off Pin Yes

Error Flag No

SoftStart No

Sync Pin No

Inverting Yes

Flyback No

RegType Switching Regulator

Temperature Min -40 deg C

Temperature Max 125 deg C

Adjustable Output Yes, No

Adj Switch Frequency No

PWM Mode Voltage

Topology Buck

Special Features SIMPLE SWITCHER regulator

Step-Down Yes

Multiple Output Capability No

Output Power Undefined Watt

Output Voltage 3.3, Undefined, 12, 15, 5 Volt

Output Range 15V, 5V, 12V, 1.23V to 65V, 3.3V

Switching Frequency 52 kHz

Regulator Family SIMPLE SWITCHER

Synchronous Rectification No

Typical Performance

*click for larger image

WEBENCH Live Simulation!

LM2576
6.00 <=	V in Lower V	<=	V in Upper V	<= 40.00
V out	1.24 <=		V	<= 37.00
I out			A	<= 3.00
Ambient Temperature			°C	<= 100
What are WEBENCH® tools?

Also Recommended

LM25005▲	Enhanced Package, More Efficient And Better Transient Response
LM25576▲	Enhanced Package, More Efficient And Better Transient Response
LM2596▲	More Efficient
LM2599▲	Improved Switching Frequency, And Efficiency
LM2673▲	Much Improved Switching Frequency
LM2676▲	Much Improved Efficiency And Switching Frequency
LM2696▲	Higher Efficiency, Enhanced Package, Better Transient Response
LM5005▲	Higher Input Voltage, Higher Switching Frequency With Sync

Additional Resources

Application Notes

Block Diagram

click for larger image

Datasheet

RoHS Compliance Information	Size in Kbytes	Date
LM2576/LM2576HV Series SIMPLE SWITCHER® 3A Step-Down Voltage Regulator	750 Kbytes	3-Aug-04	Download
LM2576/LM2576HV Series SIMPLE SWITCHER® 3A Step-Down Voltage Regulator (Japanese)	369 Kbytes

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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

LM2576T-12

5

NOPB
STD

1
1

NA
NA

N/A

Full production

N/A

Samples

Buy Now

1K+

$1.44

rail
of
45

NSUZXYTTE#
LM2576T
-12 P+

12 weeks

7500

LM2576T-15

5

NOPB
STD

1
1

NA
NA

N/A

Full production

N/A

Buy Now

1K+

$1.44

rail
of
45

NSUZXYTTE#
LM2576T
-15 P+

6 weeks

2000

LM2576T-3.3

5

NOPB

1

NA

N/A

Full production

N/A

Samples

Buy Now

1K+

$1.44

rail
of
45

NSUZXYTTE#
LM2576T
-3.3 P+

6 weeks

1000

LM2576T-5.0

5

NOPB
STD

1
1

NA
NA

N/A

Full production

N/A

Samples

Buy Now

1K+

$1.44

rail
of
45

NSUZXYTTE#
LM2576T
-5.0 P+

6 weeks

500

LM2576T-ADJ

5

NOPB
STD

1
1

NA
NA

N/A

Full production

N/A

Samples

Buy Now

1K+

$1.44

rail
of
45

NSUZXYTTE#
LM2576T
-ADJ P+

6 weeks

500

LM2576S-12

5

NOPB
STD

3
3

245
235

N/A

Full production

N/A

Buy Now

1K+

$1.44

rail
of
45

NSUZXYTTE#
LM2576S
-12 P+

6 weeks

1000

LM2576S-3.3

5

NOPB

3

245

N/A

Full production

N/A

Samples

Buy Now

1K+

$1.44

rail
of
45

NSUZXYTTE#
LM2576S
-3.3 P+

6 weeks

2000

LM2576S-5.0

5

NOPB
STD

3
3

245
235

N/A

Full production

N/A

Samples

Buy Now

1K+

$1.44

rail
of
45

NSUZXYTTE#
LM2576S
-5.0 P+

6 weeks

500

LM2576S-ADJ

5

NOPB
STD

3
3

245
235

N/A

Full production

N/A

Samples

Buy Now

1K+

$1.44

rail
of
45

NSUZXYTTE#
LM2576S
-ADJ P+

8 weeks

500

LM2576SX-12

5

NOPB

3

245

N/A

Lifetime buy

N/A

Buy Now

1K+

$1.44

reel
of
500

NSUZXYTTE#
LM2576S
-12 P+

8 weeks

2500

LM2576SX-3.3

5

NOPB
STD

3
3

245
235

N/A

Full production

N/A

Buy Now

1K+

$1.44

reel
of
500

NSUZXYTTE#
LM2576S
-3.3 P+

6 weeks

2000

LM2576SX-5.0

5

NOPB
STD

3
3

245
235

N/A

Full production

N/A

Buy Now

1K+

$1.44

reel
of
500

NSUZXYTTE#
LM2576S
-5.0 P+

6 weeks

1000

LM2576SX-ADJ

5

NOPB
STD

3
3

245
235

N/A

Full production

N/A

Buy Now

1K+

$1.44

reel
of
500

NSUZXYTTE#
LM2576S
-ADJ P+

6 weeks

2500

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM2576HVS-15	LM22676MR-ADJ	NATIONAL SEMICONDUCTOR	16 Nov 2008
LM2576HVSX-15	LM22676MRX-ADJ	NATIONAL SEMICONDUCTOR	16 Nov 2008
LM2576HVT-3.3	LM22676MR-ADJ	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM2576S-15	LM22676MR-ADJ	NATIONAL SEMICONDUCTOR	16 Nov 2008
LM2576SX-12	LM22676TJX-ADJ	NATIONAL SEMICONDUCTOR	01 Dec 2009

General Description

The LM2576 series of regulators are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching regulator, capable of driving 3A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5V, 12V, 15V, and an adjustable output version.

Requiring a minimum number of external components, these regulators are simple to use and include internal frequency compensation and a fixed-frequency oscillator.

The LM2576 series offers a high-efficiency replacement for popular three-terminal linear regulators. It substantially reduces the size of the heat sink, and in some cases no heat sink is required.

A standard series of inductors optimized for use with the LM2576 are available from several different manufacturers. This feature greatly simplifies the design of switch-mode power supplies.

Other features include a guaranteed ±4% tolerance on output voltage within specified input voltages and output load conditions, and ±10% on the oscillator frequency. External shutdown is included, featuring 50 µA (typical) standby current. The output switch includes cycle-by-cycle current limiting, as well as thermal shutdown for full protection under fault conditions.

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM2576S-12	SLM	0	44046	0	0	3532500	1	1002356520
LM2576S-15	SLM	0	44046	0	0	3532500	1	1002356520
LM2576S-3.3	SLM	0	44046	0	0	3532500	1	1002356520
LM2576S-5.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2576S-ADJ	SLM	0	44046	0	0	3532500	1	1002356520
LM2576SX-12	SLM	0	44046	0	0	3532500	1	1002356520
LM2576SX-15	SLM	0	44046	0	0	3532500	1	1002356520
LM2576SX-3.3	SLM	0	44046	0	0	3532500	1	1002356520
LM2576SX-5.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2576SX-ADJ	SLM	0	44046	0	0	3532500	1	1002356520
LM2576T-12	SLM	0	44046	0	0	3532500	1	1002356520
LM2576T-15	SLM	0	44046	0	0	3532500	1	1002356520
LM2576T-3.3	SLM	0	44046	0	0	3532500	1	1002356520
LM2576T-5.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2576T-ADJ	SLM	0	44046	0	0	3532500	1	1002356520

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

Title	Size in Kbytes	Date
SimpleSwitcher® DC-DC Converters Design Software			View

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Application Notes

Title	Size in Kbytes	Date
AN-946: Application Note 946 High-Efficiency 3A Battery Chargers Use LM2576 Regulators	109 Kbytes	3-Oct-02	Download
AN-946 (Japanese): Application Note 946 High-Efficiency 3A Battery Chargers Use LM2576 Regulators	72 Kbytes
AN-776: Application Note 776 20 Watt Simple Switcher Forward Converter	459 Kbytes	26-Sep-02	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

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More Application Notes

Title	Size in Kbytes	Date
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
AN-1229 (Chinese): Application Note 1229 SIMPLE SWITCHER PCB Layout Guidelines	668 Kbytes
AN-777: Application Note 777 LM2577 Three Output, Isolated Flyback Regulator	112 Kbytes	26-Sep-02	Download

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[Information as of 7-Nov-2009]