Features: `3.3V,5V,12V,and adjustable output versions
`Adjustable version output voltage range,1.2V to 37V (57V for HV version) ±4% max overl ine and load conditions
`Guaranteed 0.5A output current
`Available in 8-pin surface mount and DIP-8 package
`Input voltage range up to 60V
`150 kHzf ixed frequency internal oscillator
`Shutdown /Soft-start
`Out of regulation error flag
`Error output delay
`BiasSupplyPin (VBS) for internal circuitry improves efficiency at high input voltages
`Lowpowerstandbymode,IQ typically 85A
`High Efficiency
`Uses readily available standard inductors
`Thermal shutdown and current limit protection
Application·Simple high-efficiency step-down (buck) regulator
·Efficient pre-regulator for linear regulators
·On-card switching regulators
·Positive to Negative converterSpecifications`MaximumSupplyVoltage(VIN)
LM2597....................45V
LM2597HV...................60V
`SD/SS Pin InputVoltage(Note2)........6V
`Delay Pin Voltage (Note2)...........1.5V
`Flag Pin Voltage................-0.3V 45V
`BiasSupply Voltage(VBS) ...........-0.3 V 30V
`Feedback Pin Voltage.............-0.3 V +25V
`Output Voltage to Ground
(SteadyState).................-1V
`Power Dissipation................Internallylimited
`Storage Temperature Range ..........-65 to+150
| 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 |
Yes |
| SoftStart |
Yes |
| 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, error output delay |
| 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 |
| AEC Q-100 Automotive Grade |
Undefined |
| Synchronous Rectification |
No |
| View Using Catalog |
DescriptionThe LM2597/LM2597HV 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 an 8-lead DIP and an 8-lead surface mount package.
This series of switching regulators is similar to the LM2594 series, with additional supervisory and performance features added.
Requiring a minimum number of external components, these regulators are simple to use and include internal frequency compensation†, improved line and load specifications, fixed-frequency oscillator, Shutdown# /Soft-start, error flag delay and error flag output.
The LM2597/LM2597HV 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 LM2597/LM2597HV 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 85µA standby current. Self protection features include a two stage current limit for the output switch and an over temperature shutdown for complete protection under fault conditions.
The LM2597HV is for use in applications requiring and input voltage up to 60V.
Reliability Metrics
| Part Number |
Process |
EFR Reject |
EFR Sample Size |
PPM |
LTA Rejects |
LTA Device Hours |
FITS |
MTTF (Hours) |
| LM2597M-12 |
LB300 |
0 |
32249 |
0 |
0 |
3406500 |
2 |
966603676 |
| LM2597M-3.3 |
LB300 |
0 |
32249 |
0 |
0 |
3406500 |
2 |
966603676 |
| LM2597M-5.0 |
LB300 |
0 |
32249 |
0 |
0 |
3406500 |
2 |
966603676 |
| LM2597M-ADJ |
LB300 |
0 |
32249 |
0 |
0 |
3406500 |
2 |
966603676 |
| LM2597MX-12 |
LB300 |
0 |
32249 |
0 |
0 |
3406500 |
2 |
966603676 |
| LM2597MX-3.3 |
LB300 |
0 |
32249 |
0 |
0 |
3406500 |
2 |
966603676 |
| LM2597MX-5.0 |
LB300 |
0 |
32249 |
0 |
0 |
3406500 |
2 |
966603676 |
| LM2597MX-ADJ |
LB300 |
0 |
32249 |
0 |
0 |
3406500 |
2 |
966603676 |
| LM2597N-12 |
LB300 |
0 |
32249 |
0 |
0 |
3406500 |
2 |
966603676 |
| LM2597N-3.3 |
LB300 |
0 |
32249 |
0 |
0 |
3406500 |
2 |
966603676 |
| LM2597N-5.0 |
LB300 |
0 |
32249 |
0 |
0 |
3406500 |
2 |
966603676 |
| LM2597N-ADJ |
LB300 |
0 |
32249 |
0 |
0 |
3406500 |
2 |
966603676 |
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 |
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.
|
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
640){this.height=this.height*640/this.width;this.width=640;}' border="0" alt=" Connection Diagram"> |
215 Kbytes |
|
|
If you have trouble printing or viewing PDF file(s), see Printing Problems.
|
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
640){this.height=this.height*640/this.width;this.width=640;}' border="0" alt=" Connection Diagram"> |
304 Kbytes |
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|
AN-1229 (Chinese): Application Note 1229 SIMPLE SWITCHER PCB Layout Guidelines
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668 Kbytes |
|
640){this.height=this.height*640/this.width;this.width=640;}' border="0" alt=" Connection Diagram"> |
| 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
640){this.height=this.height*640/this.width;this.width=640;}' border="0" alt=" Connection Diagram"> |
85 Kbytes |
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| 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
640){this.height=this.height*640/this.width;this.width=640;}' border="0" alt=" Connection Diagram"> |
442 Kbytes |
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AN-1566 (Chinese): Application Note 1566 Techniques for Thermal Analysis of Switching Power Supply Designs
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282 Kbytes |
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640){this.height=this.height*640/this.width;this.width=640;}' border="0" alt=" Connection Diagram"> |
| 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 |
If you have trouble printing or viewing PDF file(s), see Printing Problems.
|
LM2597 Data Sheet
