Features • 3.3V, 5V, 12V, and adjustable output versions • Adjustable version output voltage range, 1.2V to 37V (57V for HV version)±4% max over line 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 kHz fixed frequency internal oscillator • Shutdown# /Soft-start • Out of regulation error flag • Error output delay • Bias Supply Pin (VBS) for internal circuitry improves efficiency at high input voltages • Low power standby mode, IQ typically 85 µA • High Efficiency • Uses readily available standard inductors • Thermal shutdown and current limit protection Description The 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 85 µA 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. Applications • Simple high-efficiency step-down (buck) regulator • Efficient pre-regulator for linear regulators • On-card switching regulators • Positive to Negative converter

LM2597   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 LM2598▲ 1.0A Version LM2671▲ Higher Switching Frequency (260 - 400 KHz) MY BRIEFCASE                                       Click any "Briefcase" icon to add an item

Typical Application click for larger image	Block Diagram click for larger image
Typical Performance *click for larger image

Datasheet

Title		Size	Date	Other Language
	LM2597/LM2597HV SIMPLE SWITCHER Power Converter 150 kHz 0.5A Step-Down Voltage Regulator, with Features	900 Kbytes	23-Jan-01	日本語

Featured Application Notes

Title		Size	Date	Other Language
	AN-1061: Application Note 1061 Power Conversion in Line-Powered Equipment	162 Kbytes	1-Oct-02	日本語

More Application Notes

Title		Size	Date	Other Language
	AN-1229: Application Note 1229 SIMPLE SWITCHER PCB Layout Guidelines	229 Kbytes	1-May-04	日本語 中文
	AN-1082: Application Note 1082 Adjust or Synchronize LM2586/88 Switching Frequency	50 Kbytes	4-Oct-04	日本語
	AN-1118: AN-1118 Simple Regulator Provides ±12V from 5V Source	51 Kbytes	4-Oct-04
	AN-1081: Application Note 1081 A Low Cost, Low Parts-Count DC/DC Converter With Multiple Outputs	74 Kbytes	4-Oct-04
	AN-1253: Application Note 1253 Wide-Input, High Voltage Buck Converter	144 Kbytes	25-Sep-02
	AN-1566: Application Note 1566 Techniques for Thermal Analysis of Switching Power Supply Designs	370 Kbytes	7-Feb-07	日本語 中文
	AN-1207: Application Note 1207 LM2593HV Evaluation Board	219 Kbytes	10-May-04
	AN-1797: Application Note 1797 TO-263 THIN Package	2716 Kbytes	10-Mar-08	日本語 中文

Design Tools

Title	Size	Date
SimpleSwitcher® DC-DC Converters Design Software
Power Reference Design Library

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM2597M-12	LB300	0	33664	0	0	3830500	1	1086914834
LM2597M-3.3	LB300	0	33664	0	0	3830500	1	1086914834
LM2597M-5.0	LB300	0	33664	0	0	3830500	1	1086914834
LM2597M-ADJ	LB300	0	33664	0	0	3830500	1	1086914834
LM2597MX-12	LB300	0	33664	0	0	3830500	1	1086914834
LM2597MX-3.3	LB300	0	33664	0	0	3830500	1	1086914834
LM2597MX-5.0	LB300	0	33664	0	0	3830500	1	1086914834
LM2597MX-ADJ	LB300	0	33664	0	0	3830500	1	1086914834
LM2597N-12	LB300	0	33664	0	0	3830500	1	1086914834
LM2597N-3.3	LB300	0	33664	0	0	3830500	1	1086914834
LM2597N-5.0	LB300	0	33664	0	0	3830500	1	1086914834
LM2597N-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.

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