LM2594 - SIMPLE SWITCHER Power Converter 150 KHz 0.5A Step-Down Voltage Regulator

LM2594 - SIMPLE SWITCHER Power Converter 150 KHz 0.5A Step-Down Voltage Regulator

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

Features

•	3.3V, 5V, 12V, and adjustable output versions
•	Adjustable version output voltage range, 1.2V to 37V (57V for the HV version)±4% max over line and load conditions
•	Available in 8-pin surface mount and DIP-8 package
•	Guaranteed 0.5A output current
•	Input voltage range up to 60V
•	Requires only 4 external components
•	150 kHz fixed frequency internal oscillator
•	TTL Shutdown capability
•	Low power standby mode, I_Q typically 85 µA
•	High Efficiency
•	Uses readily available standard inductors
•	Thermal shutdown and current limit protection

General Description

The LM2594/LM2594HV 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. More...

Applications

•	Simple high-efficiency step-down (buck) regulator
•	Efficient pre-regulator for linear regulators
•	On-card switching regulators
•	Positive to Negative convertor

Typical Application

click for larger image

Parameters Values

Output Current 500 mA

Input Min Voltage 4.5, 7, 4.75, 15 Volt

Input Max Voltage 40 Volt

Output Min 3.3, 1.23, 12, 5 Volt

Output Max 3.3, 37, 12, 5 Volt

Frequency Min 150 kHz

Frequency Max 150 kHz

Efficiency (peak) 88, 80, 82 %

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, 5 Volt

Output Range 5V, 12V, 1.23V to 37V, 3.3V

Switching Frequency 150 kHz

Regulator Family SIMPLE SWITCHER

Synchronous Rectification No

Typical Performance

*click for larger image

WEBENCH Live Simulation!

LM2594
4.50 <=	V in Lower V	<=	V in Upper V	<= 40.00
V out	1.23 <=		V	<= 40.00
I out			A	<= 0.50
Ambient Temperature			°C	<= 100
What are WEBENCH® tools?

Also Recommended

LM2594HV▲	Up To 60V Input Voltage
LM2595▲	1A Output Current
LM2597▲	Error Flag, Softstart And Error Output Delay
LM2619▲	600Khz, Low Power, Synchronous Rectification For Higher Efficiency
LM2671▲	Has Sync Pin, Improved Switching Frequency And Efficiency
LM2674▲	260KHz Switching Frequency, Better Performance
LM5007▲	80V 0.5A Switching Regulator

Additional Resources

Application Notes

Block Diagram

click for larger image

Datasheet

RoHS Compliance Information	Size in Kbytes	Date
LM2594/LM2594HV SIMPLE SWITCHER Power Converter 150 kHz 0.5A Step-Down Voltage Regulator	739 Kbytes	22-Aug-00	Download
LM2594/LM2594HV SIMPLE SWITCHER Power Converter 150 kHz 0.5A Step-Down Voltage Regulator (Japanese)	847 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

LM2594M-12

8

NOPB
STD

1
1

260
235

Full production

N/A

Samples

Buy Now

1K+

$1.28

rail
of
95

NSZXTT
2594
M-12

16 weeks

2000

LM2594M-3.3

8

NOPB
STD

1
1

260
235

Full production

N/A

Samples

Buy Now

1K+

$1.28

rail
of
95

NSZXTT
2594
M-3.3

12 weeks

2500

LM2594M-5.0

8

NOPB
STD

1
1

260
235

Full production

N/A

Samples

Buy Now

1K+

$1.28

rail
of
95

NSZXTT
2594
M-5.0

6 weeks

2000

LM2594M-ADJ

8

NOPB
STD

1
1

260
235

Full production

N/A

Samples

Buy Now

1K+

$1.28

rail
of
95

NSZXTT
2594
M-ADJ

16 weeks

2000

LM2594MX-12

8

NOPB

1

260

Full production

N/A

Buy Now

1K+

$1.28

reel
of
2500

NSZXTT
2594
M-12

6 weeks

5000

LM2594MX-3.3

8

NOPB
STD

1
1

260
235

Full production

N/A

Buy Now

1K+

$1.28

reel
of
2500

NSZXTT
2594
M-3.3

6 weeks

5000

LM2594MX-5.0

8

NOPB
STD

1
1

260
235

Full production

N/A

Buy Now

1K+

$1.28

reel
of
2500

NSZXTT
2594
M-5.0

6 weeks

3000

LM2594MX-ADJ

8

NOPB
STD

1
1

260
235

Full production

N/A

Buy Now

1K+

$1.28

reel
of
2500

NSZXTT
2594
M-ADJ

6 weeks

7500

LM2594N-12

8

NOPB
STD

1
1

NA
NA

Full production

N/A

Samples

Buy Now

1K+

$1.28

rail
of
40

NSUZXYTTE#
LM2594N
-12 P+

8 weeks

1000

LM2594N-3.3

8

NOPB

1

NA

Full production

N/A

Samples

Buy Now

1K+

$1.28

rail
of
40

NSUZXYTTE#
LM2594N
-3.3 P+

12 weeks

1000

LM2594N-5.0

8

NOPB
STD

1
1

NA
NA

Full production

N/A

Samples

Buy Now

1K+

$1.28

rail
of
40

NSUZXYTTE#
LM2594N
-5.0 P+

12 weeks

2000

LM2594N-ADJ

8

NOPB
STD

1
1

NA
NA

Full production

N/A

Samples

Buy Now

1K+

$1.28

rail
of
40

NSUZXYTTE#
LM2594N
-ADJ P+

6 weeks

1000

LM2594HVADJ MDC

Lifetime buy

N/A

tray
of
N/A

6 weeks

N/A

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM2594HVADJ MDC	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009

General Description

The LM2594/LM2594HV 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, and an adjustable output version, and are packaged in a 8-lead DIP and a 8-lead surface mount package.

Requiring a minimum number of external components, these regulators are simple to use and feature internal frequency compensation†, a fixed-frequency oscillator, and improved line and load regulation specifications.

The LM2594/LM2594HV series operates at a switching frequency of 150 kHz thus allowing smaller sized filter components than what would be needed with lower frequency switching 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 (both through hole and surface mount types) are available from several different manufacturers optimized for use with the LM2594/LM2594HV series. This feature greatly simplifies the design of switch-mode power supplies.

Other features include a guaranteed ±4% tolerance on output voltage under all conditions of input voltage and output load conditions, and ±15% on the oscillator frequency. External shutdown is included, featuring typically 85 µA standby current. Self protection features include a two stage frequency reducing current limit for the output switch and an over temperature shutdown for complete protection under fault conditions.

The LM2594HV is for applications requiring an input voltage up to 60V.

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM2594HVADJ MDC	LB300	0	33664	0	0	3830500	1	1086914834
LM2594M-12	LB300	0	33664	0	0	3830500	1	1086914834
LM2594M-3.3	LB300	0	33664	0	0	3830500	1	1086914834
LM2594M-5.0	LB300	0	33664	0	0	3830500	1	1086914834
LM2594M-ADJ	LB300	0	33664	0	0	3830500	1	1086914834
LM2594MX-12	LB300	0	33664	0	0	3830500	1	1086914834
LM2594MX-3.3	LB300	0	33664	0	0	3830500	1	1086914834
LM2594MX-5.0	LB300	0	33664	0	0	3830500	1	1086914834
LM2594MX-ADJ	LB300	0	33664	0	0	3830500	1	1086914834
LM2594N-12	LB300	0	33664	0	0	3830500	1	1086914834
LM2594N-3.3	LB300	0	33664	0	0	3830500	1	1086914834
LM2594N-5.0	LB300	0	33664	0	0	3830500	1	1086914834
LM2594N-ADJ	LB300	0	33664	0	0	3830500	1	1086914834

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-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-1082: Application Note 1082 Adjust or Synchronize LM2586/88 Switching Frequency	50 Kbytes	4-Oct-04	Download
AN-1082 (Japanese): Application Note 1082 Adjust or Synchronize LM2586/88 Switching Frequency	85 Kbytes
AN-1118: AN-1118 Simple Regulator Provides ±12V from 5V Source	51 Kbytes	4-Oct-04	Download
AN-1081: Application Note 1081 A Low Cost, Low Parts-Count DC/DC Converter With Multiple Outputs	74 Kbytes	4-Oct-04	Download
AN-1253: Application Note 1253 Wide-Input, High Voltage Buck Converter	144 Kbytes	25-Sep-02	Download
AN-1566: Application Note 1566 Techniques for Thermal Analysis of Switching Power Supply Designs	370 Kbytes	7-Feb-07	Download
AN-1566 (Japanese): Application Note 1566 Techniques for Thermal Analysis of Switching Power Supply Designs	442 Kbytes
AN-1566 (Chinese): Application Note 1566 Techniques for Thermal Analysis of Switching Power Supply Designs	282 Kbytes
AN-1207: Application Note 1207 LM2593HV Evaluation Board	219 Kbytes	10-May-04	Download
AN-1797: Application Note 1797 TO-263 THIN Package	2716 Kbytes	10-Mar-08	Download
AN-1797 (Japanese): Application Note 1797 TO-263 THIN Package	1424 Kbytes

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[Information as of 8-Nov-2009]