National Semiconductor, The Sight And Sound Of Information, Welcomes You

Products > Analog - Regulators > SwitchingRegulators > LM2574

LM2574 Product Folder

SIMPLE SWITCHER 0.5A Step-Down Voltage Regulator

See Also:		LM2594 - higher efficiency, smaller solution size
		LM2597 - higher efficiency, smaller solution size
		LM2674 - very high efficiency, much smaller solution size
		LM2671 - HIGHER EFFICIENCY, SMALLER SOLUTION SIZE.

Generic P/N 2574

General
Description

Package
& Models

Samples
& Pricing

Reliability
Metrics

Application
Notes

WEBENCH Live Simulation!

LM2574 Webench™ Custom Design/Analyze/Build It
4.8 <=	V in Lower V	<=	V in Upper V	<= 40.0
V out	1.2 <=		V	<= 37.0
I out			A	<= 0.50
Ambient Temperature			°C	<= 100
What is Webench?

Parametric Table

Temperature Min (deg C)	-40
Temperature Max (deg C)	125
Multiple Output Capability	No
On/Off Pin	Yes
Error Flag	No
InputMin Voltage (Volt)	4
InputMax Voltage (Volt)	40, 60
Output Current (mA)	500
Output Voltage (Volt)	12, 15, 3.30, 5
Adjustable Output	No, Yes
Output Range	Undefined, 1.23V-37V
Switching Frequency (Hz)	52000
Adj Switch Frequency	No
Sync Pin	No
Efficiency (%)	88, 72, 77
Flyback	No
Inverting	Yes
Step-Up	No
Step-Down	Yes
RegType	Switching Regulator

-

Datasheet

Title	Size in Kbytes	Date	View Online	Download	Receive via Email
LM2574 LM2574HV SIMPLE SWITCHER 0.5A Step-Down Voltage Regulator	639 Kbytes	30-Jun-99	View Online	Download	Receive via Email
LM2574 LM2574HV SIMPLE SWITCHER 0.5A Step-Down Voltage Regulator (JAPANESE)	840 Kbytes

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

Package Availability, Models, Samples & Pricing

Part Number

Package

Status

Models

Samples &
Electronic
Orders

Budgetary Pricing

Std
Pack
Size

Package
Marking

Type

Pins

MSL/Lead-Free Availability

Lead
Time

Qty

SPICE

IBIS

Qty

$US each

LM2574M-12

14

Full production

N/A

N/A

1K+

$0.72

rail
of
50

NSUZXYTT
LM2574M
-12 P+

8-10 weeks

15000

LM2574M-15

14

Full production

N/A

N/A

1K+

$0.72

rail
of
50

NSUZXYTT
LM2574M
-15 P+

3-5 weeks

15000

LM2574M-3.3

14

Full production

N/A

N/A

1K+

$0.72

rail
of
50

NSUZXYTT
LM2574M
-3.3 P+

8-10 weeks

15000

LM2574M-5.0

14

Full production

N/A

N/A

1K+

$0.72

rail
of
50

NSUZXYTT
LM2574M
-5.0 P+

8-10 weeks

15000

LM2574M-ADJ

14

Full production

N/A

N/A

1K+

$0.72

rail
of
50

NSUZXYTT
LM2574M
-ADJ P+

8-10 weeks

25000

LM2574MX-12

14

Full production

N/A

N/A

1K+

$0.72

reel
of
1000

NSUZXYTT
LM2574M
-12 P+

8-10 weeks

15000

LM2574MX-15

14

Full production

N/A

N/A

1K+

$0.72

reel
of
1000

NSUZXYTT
LM2574M
-15 P+

3-5 weeks

15000

LM2574MX-3.3

14

Full production

N/A

N/A

1K+

$0.72

reel
of
1000

NSUZXYTT
LM2574M
-3.3 P+

8-10 weeks

15000

LM2574MX-5.0

14

Full production

N/A

N/A

1K+

$0.72

reel
of
1000

NSUZXYTT
LM2574M
-5.0 P+

8-10 weeks

15000

LM2574MX-ADJ

14

Full production

N/A

N/A

1K+

$0.72

reel
of
1000

NSUZXYTT
LM2574M
-ADJ P+

8-10 weeks

50000

LM2574N-12

8

Full production

N/A

N/A

1K+

$0.72

rail
of
40

NSUZXYTT
LM2574N
-12 P+

8-10 weeks

15000

LM2574N-15

8

Full production

N/A

N/A

1K+

$0.72

rail
of
40

NSUZXYTT
LM2574N
-15 P+

3-5 weeks

15000

LM2574N-3.3

8

Full production

N/A

N/A

1K+

$0.72

rail
of
40

NSUZXYTT
LM2574N
-3.3 P+

8-10 weeks

15000

LM2574N-5.0

8

Full production

N/A

N/A

1K+

$0.72

rail
of
40

NSUZXYTT
LM2574N
-5.0 P+

8-10 weeks

15000

LM2574N-ADJ

8

Full production

N/A

N/A

1K+

$0.72

rail
of
40

NSUZXYTT
LM2574N
-ADJ P+

8-10 weeks

25000

LM2574-5.0 MDA

Full production

N/A

N/A

tray
of
N/A

-

N/A

0

LM2574-5.0 MWA

Full production

N/A

N/A

wafer jar
of
N/A

-

N/A

0

LM2574-12 MDC

Full production

N/A

N/A

tray
of
N/A

-

N/A

0

LM2574-15 MDC

Full production

N/A

N/A

tray
of
N/A

-

N/A

0

LM2574-3.3 MDC

Full production

N/A

N/A

tray
of
N/A

-

N/A

0

LM2574-ADJ MDC

Full production

N/A

N/A

tray
of
N/A

-

N/A

0

LM2574HV-12 MDC

Full production

N/A

N/A

tray
of
N/A

-

N/A

0

LM2574HV-15 MDC

Full production

N/A

N/A

tray
of
N/A

-

N/A

0

LM2574HV3.3 MDC

Full production

N/A

N/A

tray
of
N/A

-

N/A

0

LM2574HVADJ MDC

Full production

N/A

N/A

tray
of
N/A

-

N/A

0

LM2574-12 MWC

Full production

N/A

N/A

wafer jar
of
N/A

-

N/A

0

LM2574-15 MWC

Full production

N/A

N/A

wafer jar
of
N/A

-

N/A

0

LM2574-3.3 MWC

Full production

N/A

N/A

wafer jar
of
N/A

-

N/A

0

LM2574-ADJ MWC

Full production

N/A

N/A

wafer jar
of
N/A

-

N/A

0

LM2574HV-12 MWC

Full production

N/A

N/A

wafer jar
of
N/A

-

N/A

0

LM2574HV-15 MWC

Full production

N/A

N/A

wafer jar
of
N/A

-

N/A

0

LM2574HV3.3 MWC

Full production

N/A

N/A

wafer jar
of
N/A

-

N/A

0

LM2574HVADJ MWC

Full production

N/A

N/A

wafer jar
of
N/A

-

N/A

0

General Description

The LM2574 series of regulators are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching regulator, capable of driving a 0.5A 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 LM2574 series offers a high-efficiency replacement for popular three-terminal linear regulators. Because of its high efficiency, the copper traces on the printed circuit board are normally the only heat sinking needed.

A standard series of inductors optimized for use with the LM2574 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.

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 0.5A 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

Applications

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

Reliability Metrics

Part Number	Process	Early Failure Rate - Rejects	Sample Size (EFR)	PPM *	Rel. Rejects	Device Hours	Long Term Failure Rates (FITS)	MTTF
LM2574-12 MDC	SLM	0	35000	0	0	1500000	3	424108012
LM2574-12 MWC	SLM	0	35000	0	0	1500000	3	424108012
LM2574-15 MDC	SLM	0	35000	0	0	1500000	3	424108012
LM2574-15 MWC	SLM	0	35000	0	0	1500000	3	424108012
LM2574-3.3 MDC	SLM	0	35000	0	0	1500000	3	424108012
LM2574-3.3 MWC	SLM	0	35000	0	0	1500000	3	424108012
LM2574-5.0 MDA	SLM	0	35000	0	0	1500000	3	424108012
LM2574-5.0 MWA	SLM	0	35000	0	0	1500000	3	424108012
LM2574-ADJ MDC	SLM	0	35000	0	0	1500000	3	424108012
LM2574-ADJ MWC	SLM	0	35000	0	0	1500000	3	424108012
LM2574HV-12 MDC	SLM	0	35000	0	0	1500000	3	424108012
LM2574HV-12 MWC	SLM	0	35000	0	0	1500000	3	424108012
LM2574HV-15 MDC	SLM	0	35000	0	0	1500000	3	424108012
LM2574HV-15 MWC	SLM	0	35000	0	0	1500000	3	424108012
LM2574HV3.3 MDC	SLM	0	35000	0	0	1500000	3	424108012
LM2574HV3.3 MWC	SLM	0	35000	0	0	1500000	3	424108012
LM2574HVADJ MDC	SLM	0	35000	0	0	1500000	3	424108012
LM2574HVADJ MWC	SLM	0	35000	0	0	1500000	3	424108012
LM2574M-12	SLM	0	35000	0	0	1500000	3	424108012
LM2574M-15	SLM	0	35000	0	0	1500000	3	424108012
LM2574M-3.3	SLM	0	35000	0	0	1500000	3	424108012
LM2574M-5.0	SLM	0	35000	0	0	1500000	3	424108012
LM2574M-ADJ	SLM	0	35000	0	0	1500000	3	424108012
LM2574MX-12	SLM	0	35000	0	0	1500000	3	424108012
LM2574MX-15	SLM	0	35000	0	0	1500000	3	424108012
LM2574MX-3.3	SLM	0	35000	0	0	1500000	3	424108012
LM2574MX-5.0	SLM	0	35000	0	0	1500000	3	424108012
LM2574MX-ADJ	SLM	0	35000	0	0	1500000	3	424108012
LM2574N-12	SLM	0	35000	0	0	1500000	3	424108012
LM2574N-15	SLM	0	35000	0	0	1500000	3	424108012
LM2574N-3.3	SLM	0	35000	0	0	1500000	3	424108012
LM2574N-5.0	SLM	0	35000	0	0	1500000	3	424108012
LM2574N-ADJ	SLM	0	35000	0	0	1500000	3	424108012

For more information on Reliablitity Metrics, please click here.

Design Tools

Title	Size in Kbytes	Date	View Online	Download	Receive via Email
SimpleSwitcher® DC-DC Converters Design Software	9 Kbytes	28-Jul-2003	View

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

Application Notes

Title	Size in Kbytes	Date	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-1149: Application Note 1149 Layout Guidelines for Switching Power Supplies	113 Kbytes	26-Sep-02	View Online	Download	Receive via Email
AN-1229: Application Note 1229 SIMPLE SWITCHER PCB Layout Guidelines	229 Kbytes	1-Oct-02	View Online	Download	Receive via Email
AN-1246: Application Note 1246 Stresses in Wide Input DC-DC Converters	272 Kbytes	26-Sep-02	View Online	Download	Receive via Email
AN-556: Application Note 556 Introduction to Power Supplies	159 Kbytes	25-Sep-02	View Online	Download	Receive via Email

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

[Information as of 15-Jan-2004]