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, IQ 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


ParametersValues
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


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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


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Also Recommended
LM2594HVUp To 60V Input Voltage
LM25951A Output Current
LM2597Error Flag, Softstart And Error Output Delay
LM2619600Khz, Low Power, Synchronous Rectification For Higher Efficiency
LM2671Has Sync Pin, Improved Switching Frequency And Efficiency
LM2674260KHz Switching Frequency, Better Performance
LM500780V 0.5A Switching Regulator
Additional Resources
Design Tools

Application Notes


Block Diagram


click for larger image



Datasheet
RoHS Compliance Information Size in KbytesDate Click link below to Download
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   Download

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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
LM2594M-12SOIC NARROW8NOPB
STD
1
1
260
235
RoHS Download Full productionN/A
Samples
Buy Now
1K+$1.28rail
of
95
NSZXTT
2594
M-12
16 weeks2000
LM2594M-3.3SOIC NARROW8NOPB
STD
1
1
260
235
RoHS Download Full productionN/A
Samples
Buy Now
1K+$1.28rail
of
95
NSZXTT
2594
M-3.3
12 weeks2500
LM2594M-5.0SOIC NARROW8NOPB
STD
1
1
260
235
RoHS Download Full productionN/A
Samples
Buy Now
1K+$1.28rail
of
95
NSZXTT
2594
M-5.0
6 weeks2000
LM2594M-ADJSOIC NARROW8NOPB
STD
1
1
260
235
RoHS Download Full productionN/A
Samples
Buy Now
1K+$1.28rail
of
95
NSZXTT
2594
M-ADJ
16 weeks2000
LM2594MX-12SOIC NARROW8NOPB1260RoHS Download Full productionN/A
 
Buy Now
1K+$1.28reel
of
2500
NSZXTT
2594
M-12
6 weeks5000
LM2594MX-3.3SOIC NARROW8NOPB
STD
1
1
260
235
RoHS Download Full productionN/A
 
Buy Now
1K+$1.28reel
of
2500
NSZXTT
2594
M-3.3
6 weeks5000
LM2594MX-5.0SOIC NARROW8NOPB
STD
1
1
260
235
RoHS Download Full productionN/A
 
Buy Now
1K+$1.28reel
of
2500
NSZXTT
2594
M-5.0
6 weeks3000
LM2594MX-ADJSOIC NARROW8NOPB
STD
1
1
260
235
RoHS Download Full productionN/A
 
Buy Now
1K+$1.28reel
of
2500
NSZXTT
2594
M-ADJ
6 weeks7500
LM2594N-12MDIP8NOPB
STD
1
1
NA
NA
RoHS Download Full productionN/A
Samples
Buy Now
1K+$1.28rail
of
40
NSUZXYTTE#
LM2594N
-12 P+
8 weeks1000
LM2594N-3.3MDIP8NOPB1NARoHS Download Full productionN/A
Samples
Buy Now
1K+$1.28rail
of
40
NSUZXYTTE#
LM2594N
-3.3 P+
12 weeks1000
LM2594N-5.0MDIP8NOPB
STD
1
1
NA
NA
RoHS Download Full productionN/A
Samples
Buy Now
1K+$1.28rail
of
40
NSUZXYTTE#
LM2594N
-5.0 P+
12 weeks2000
LM2594N-ADJMDIP8NOPB
STD
1
1
NA
NA
RoHS Download Full productionN/A
Samples
Buy Now
1K+$1.28rail
of
40
NSUZXYTTE#
LM2594N
-ADJ P+
6 weeks1000
LM2594HVADJ MDCUnpackaged DieLifetime buyN/A
  CALLtray
of
N/A
-
6 weeksN/A

Obsolete Versions

Obsolete PartAlternate Part or SupplierSourceLast 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 MDCLB30003366400383050011086914834
LM2594M-12LB30003366400383050011086914834
LM2594M-3.3LB30003366400383050011086914834
LM2594M-5.0LB30003366400383050011086914834
LM2594M-ADJLB30003366400383050011086914834
LM2594MX-12LB30003366400383050011086914834
LM2594MX-3.3LB30003366400383050011086914834
LM2594MX-5.0LB30003366400383050011086914834
LM2594MX-ADJLB30003366400383050011086914834
LM2594N-12LB30003366400383050011086914834
LM2594N-3.3LB30003366400383050011086914834
LM2594N-5.0LB30003366400383050011086914834
LM2594N-ADJLB30003366400383050011086914834

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    

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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-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  
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   Download
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   Download
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   Download

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

[Information as of 8-Nov-2009]