Features • Wide input voltage range: 4.5V to 42V • Internally compensated voltage mode control • Stable with low ESR ceramic capacitors • 200 mΩ N-channel MOSFET • Output voltage options: •  -ADJ (outputs as low as 1.285V) •  -5.0 (output fixed to 5V) • ±1.5% feedback reference accuracy • Switching frequency of 500 kHz, adjustable between 200 kHz and 1 MHz • -40°C to 125°C operating junction temperature range • Precision enable pin • Integrated boot diode • Adjustable soft-start • Fully WEBENCH ® enabled • Step-down and inverting buck-boost applications Description The LM22671 series of regulators are monolithic integrated circuits which provide all of the active functions for a step-down (buck) switching regulator capable of driving up to 500 mA loads with excellent line and load regulation characteristics. High efficiency (>90%) is obtained through the use of a low ON-resistance N-channel MOSFET. The series consists of a fixed 5V output and an adjustable version. The SIMPLE SWITCHER ® concept provides for an easy to use complete design using a minimum number of external components and National’s WEBENCH ® design tool. National’s WEBENCH ® tool includes features such as external component calculation, electrical simulation, thermal simulation, and Build-It boards for easy design-in. The switching clock frequency is provided by an internal fixed frequency oscillator which operates at 500 kHz. The switching frequency can also be adjusted with an external resistor or synchronized to an external clock up to 1 MHz. It is also possible to self-synchronize multiple regulators to share the same switching frequency. The LM22671 series also has built in thermal shutdown, current limiting and an enable control input that can power down the regulator to a low 25 µA quiescent current standby condition. An adjustable soft-start feature is provided by selecting an appropriate external soft-start capacitor. Applications • Industrial Control • Telecom and Datacom Systems • Embedded Systems • Automotive Telematics and Body Electronics • Conversions from Standard 24V, 12V and 5V Input Rails

LM22671   4.50 <= V in Lower  V   <= V in Upper  V   <= 42.00 V out 1.28 <=  V <= 37.00 I out    A <= 0.50 Ambient Temperature  °C <= 100 What are WEBENCH® tools? Also Recommended LM22670▲ 3A, Features Adjustable Switching Frequency Or Frequency Sync Up To 1MHz And Precision Enable LM22672▲ 1A Version LM22673▲ 3A, Features Adjustable Soft-Start And Adjustable Current Limit LM22674▲ Features Precision Enable Only LM22677▲ 5A, Features Adjustable Switching Frequency Or Frequency Sync Up To 1MHz And Precision Enable LM22679▲ 5A, Features Adjustable Soft-Start And Adjustable Current Limit LM22680▲ 2A Version MY BRIEFCASE                                       Click any "Briefcase" icon to add an item

Typical Application click for larger image	Connection Diagram click for larger image
Typical Performance click for larger image

Datasheet

Title		Size	Date	Other Language
	LM22671 500 mA SIMPLE SWITCHER®, Step-Down Voltage Regulator with Features	391 Kbytes	24-Nov-08	日本語

Featured Application Notes

Title		Size	Date	Other Language
	AN-1895: Application Note 1895 LM22671 Evaluation Board	249 Kbytes	14-Oct-08
	AN-1930: Application Note 1930 SIMPLE SWITCHER® Regulators Take Over Automotive Applications	85 Kbytes	7-Jan-09
	AN-1889: Application Note 1889 How to Measure the Loop Transfer Function of Power Supplies	612 Kbytes	14-Oct-08

More Application Notes

Title		Size	Date	Other Language
	AN-1888: Application Note 1888 LM22670 Evaluation Board Inverting Topology and Application Notes	1020 Kbytes	9-Jul-09	日本語
	AN-1896: Application Note 1896 LM22672 Evaluation Board	258 Kbytes	14-Oct-08
	AN-1891: Application Note 1891 LM22679 Evaluation Board	232 Kbytes	14-Oct-08
	AN-1894: Application Note 1894 LM22673 Evaluation Board	255 Kbytes	14-Oct-08
	AN-1892: Application Note 1892 LM22677 Evaluation Board	237 Kbytes	14-Oct-08	日本語
	AN-1885: Application Note 1885 LM22670 Evaluation Board	499 Kbytes	14-Oct-08

Design Tools

Title	Size	Date
"Downloadable LM2267x, LM22680 Quick Start Simple Switcher Component Calculator"	1413 Kbytes	12-Jan-2009

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM22671MR-5.0	ABCD5	0	5364	0	0	1626984	3	461661152
LM22671MR-ADJ	ABCD5	0	5364	0	0	1626984	3	461661152
LM22671MRE-5.0	ABCD5	0	5364	0	0	1626984	3	461661152
LM22671MRE-ADJ	ABCD5	0	5364	0	0	1626984	3	461661152
LM22671MRX-5.0	ABCD5	0	5364	0	0	1626984	3	461661152
LM22671MRX-ADJ	ABCD5	0	5364	0	0	1626984	3	461661152

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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