Features • Power stage input voltage from 1V to 16V • Control stage input voltage from 3V to 6V • Output voltage adjustable down to 0.5V • Power good flag and shutdown • Output overvoltage and undervoltage detection • External reference voltage 0.5V to 1.5V • Low-side adjustable current sensing • Adjustable soft-start • Tracking and sequencing with shutdown and soft start pins • Switching frequency from 50 kHz to 1 MHz • TSSOP-14 package Description The LM2744 is a high-speed synchronous buck regulator controller with an externally adjustable reference voltage (between 0.5V to 1.5V). It can provide simple down conversion to output voltages as low as 0.5V. Though the control sections of the IC are rated for 3 to 6V, the driver sections are designed to accept input supply rails as high as 16V. The use of adaptive non-overlapping MOSFET gate drivers helps avoid potential shoot-through problems while maintaining high efficiency. The IC is designed for the more cost-effective option of driving only N-channel MOSFETs in both the high-side and low-side positions. It senses the low-side switch voltage drop for providing a simple, adjustable current limit. The fixed-frequency voltage-mode PWM control architecture is adjustable from 50 kHz to 1 MHz with one external resistor. This wide range of switching frequency gives the power supply designer the flexibility to make better tradeoffs between component size, cost and efficiency. Features include soft-start, input undervoltage lockout (UVLO) and Power Good (based on both undervoltage and overvoltage detection). In addition, the shutdown pin of the IC can be used for providing startup delay, and the soft-start pin can be used for implementing precise tracking, for the purpose of sequencing with respect to an external rail. Applications • 3.3V Buck Regulation • Cable Modem, DSL and ADSL • Laser Jet and Ink Jet Printers • Low Voltage Power Modules • DSP, ASIC, Core and I/O • DDR Memory Termination Supply

Also Recommended LM4140 High Accuracy, Sub-Bandgap Stand-Alone Voltage Reference LP2996▲ DDR And DDR-II Linear Termination Regulator LP2997▲ DDR-II Linear Termination 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

Datasheets

Title		Size	Date	Other Language
	LM2744 Low Voltage N-Channel MOSFET Synchronous Buck Regulator Controller with External Reference	535 Kbytes	24-Apr-07

Featured Application Notes

Title		Size	Date	Other Language
	AN-1357: Application Note 1357 LM2744 Evaluation Board	1794 Kbytes	5-Oct-05	中文
	AN-1603: Application Note 1603 LM274X Reference Designs	431 Kbytes	6-Dec-07	中文

More Application Notes

Title		Size	Date	Other Language
	AN-1437: Application Note 1437 Current Limit Foldback Improves Short Circuit Protection in LM274X Family	470 Kbytes	25-May-06	中文
	AN-1573: Application Note 1573 LM2745-19A Demo Board	2572 Kbytes	17-May-07
	AN-1640: Application Note 1640 LM2743-19A Demo Board	2570 Kbytes	17-May-07	中文
	AN-1641: Application Note 1641 LM2747-19A Demo Board	2571 Kbytes	17-May-07
	AN-1325: Application Note 1325 LM2742 Evaluation Board	607 Kbytes	1-Apr-04
	AN-1449: Application Note 1449 LM2747 Evaluation Board	594 Kbytes	11-Apr-06
	AN-1385: Application Note 1385 LM2746 Evaluation Board	1743 Kbytes	1-Jun-05	中文
	AN-1356: Application Note 1356 LM2743 Evaluation Board	1785 Kbytes	5-Oct-05	日本語 中文

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Standard Pack Size
LM2744MTC/NOPB LM2744MTC RoHS Status	TSSOP	Full production Lead Time: 6 weeks	Distributor Region Qty DIGIKEY Worldwide 23 FARNELL Europe and Asia 273 RS COMPONENTS Worldwide 85	$1.15 each at 1K+ pcs	rail of 94
LM2744MTCX/NOPB LM2744MTCX RoHS Status	TSSOP	Full production Lead Time: 6 weeks	Distributor Region Qty DIGIKEY Worldwide 0	$1.15 each at 1K+ pcs	reel of 2500

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/packaging/leadfree.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/quality/green.

National's certificate of product compliance is located at RoHS Status.

Part Number(s) (NSID)	Top View	Type	Pins	MSL Rating	Peak Reflow	RoHS Status	CAD Symbols	Models	Package Marking Format
LM2744MTC/NOPB LM2744MTC		TSSOP	14	1 1	260 260	Detail	Download	N/A	NSZXYTT 2744 MTC
LM2744MTCX/NOPB LM2744MTCX		TSSOP	14	1 1	260 260	Detail	Download	N/A	NSZXYTT 2744 MTC

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/packaging/leadfree.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/quality/green.

National's certificate of product compliance is located at RoHS Status.

Design Tools

Title	Size	Date
Article - Exploit Controller Features to Optimize Power Designs

CAD Symbols and Models Download LM2744 CAD Symbols

Models N/A

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM2744MTC	ABCD150	0	34175	0	0	4234000	1	1201409060
LM2744MTCX	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.

For more information on Reliability Metrics, please click here.

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/packaging/leadfree.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/quality/green.

National's certificate of product compliance is located at RoHS Status.