Features • Easy to use control methodology • No control loop compensation required • Wide 4.5V to 35V input range • 1.239V to VIN adjustable output range • High efficiency 93% • ±1.3% (±2% over temp) internal reference • 100% duty cycle operation • Maximum operation frequency > 1MHz • Current limit protection • Dedicated enable pin (on if unconnected) • Shutdown mode draws only 7µA supply current • MSOP-8 • LM3489 is AEC-Q100 Grade 1 qualified Description The LM3489 is a high efficiency PFET switching regulator controller that can be used to quickly and easily develop a small, cost effective, switching buck regulator for a wide range of applications. The hysteretic control architecture provides for simple design without any control loop stability concerns using a wide variety of external components. The PFET architecture also allows for low component count as well as ultra-low dropout, 100% duty cycle operation. Another benefit is high efficiency operation at light loads without an increase in output ripple. A dedicated Enable Pin provides a shutdown mode drawing only 7µA. Leaving the Enable Pin unconnected defaults to on. Current limit protection can be implemented by measuring the voltage across the PFET’s RDS(ON), thus eliminating the need for a sense resistor. A sense resistor may be used to improve current limit accuracy if desired. The cycle-by-cycle current limit can be adjusted with a single resistor, ensuring safe operation over a range of output currents. Applications • Set-Top Box • DSL/Cable Modem • PC/IA • Auto PC • TFT Monitor • Battery Powered Portable Applications • Distributed Power Systems • Always On Power • High Power LED Driver • Automotive

Also Recommended LM25574▲ Integrated 42V 0.5A Buck Regulator LM25575▲ Integrated 42V 1.5A Buck Regulator LM25576▲ Integrated 42V 3A Buck Regulator 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
	LM3489/LM3489Q Hysteretic PFET Buck Controller with Enable Pin	356 Kbytes	23-Jun-08	日本語

Featured Application Notes

Title		Size	Date	Other Language
	AN-1471: Application Note 1471 LM3489 Demonstration Board	695 Kbytes	24-May-06

More Application Notes

Title		Size	Date	Other Language
	AN-1204: Application Note 1204 LM3478/LM3488 Evaluation Board	218 Kbytes	10-May-04
	AN-1756: Application Note 1756 LM3481 Evaluation Board	505 Kbytes	30-Apr-08	日本語
	AN-1227: Application Note 1227 LM3485 Evaluation Board	86 Kbytes	10-May-04
	AN-1392: Application Note 1392 LM3485 LED Demo Board	569 Kbytes	7-Jun-06	中文

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM3489MM	ABCD150	0	34175	0	0	4234000	1	1201409060
LM3489MMX	ABCD150	0	34175	0	0	4234000	1	1201409060
LM3489QMM	ABCD150	0	34175	0	0	4234000	1	1201409060
LM3489QMMX	ABCD150	0	34175	0	0	4234000	1	1201409060

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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