Features • 22V DMOS FET switch • 1.6 MHz (“X”), 0.6 MHz (“Y”) switching frequency • Low RDS(ON) DMOS FET • Switch current up to 1.8A • Wide input voltage range (2.7V–14V) • Low shutdown current (<1 µA) • 5-Lead SOT-23 package • Uses tiny capacitors and inductors • Cycle-by-cycle current limiting • Internally compensated Description The LM2731 switching regulators are current-mode boost converters operating at fixed frequencies of 1.6 MHz (“X” option) and 600 kHz (“Y” option). The use of SOT-23 package, made possible by the minimal power loss of the internal 1.8A switch, and use of small inductors and capacitors result in the industry's highest power density. The 22V internal switch makes these solutions perfect for boosting to voltages up to 20V. These parts have a logic-level shutdown pin that can be used to reduce quiescent current and extend battery life. Protection is provided through cycle-by-cycle current limiting and thermal shutdown. Internal compensation simplifies design and reduces component count. Switch Frequency X Y 1.6 MHz 0.6 MHz Applications • White LED Current Source • PDA’s and Palm-Top Computers • Digital Cameras • Portable Phones and Games • Local Boost Regulator

LM2731X   2.70 <= V in Lower  V   <= V in Upper  V   <= 14.00 V out 1.23 <=  V <= 22.00 I out    A <= 1.80 Ambient Temperature  °C <= 100 What are WEBENCH® tools? Also Recommended LM2733▲ Has A 40V / 1A Internal FET SOT-23 Package LM2735▲ Increased Switch Current At 2.1A 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
	LM2731 0.6/1.6 MHz Boost Converters With 22V Internal FET Switch in SOT-23	432 Kbytes	8-Jul-07	日本語

Featured Application Notes

Title		Size	Date	Other Language
	AN-1280: Application Note 1280 LM2731/LM2733 Evaluation Board	55 Kbytes	18-Apr-03

More Application Notes

Title		Size	Date	Other Language
	AN-1973: Application Note 1973 Benefits and Challenges of High-Frequency Regulators	348 Kbytes	25-Jun-09
	AN-1658: Application Note 1658 LM2735 BOOST and SEPIC DC-DCRegulator	408 Kbytes	26-Jun-07	日本語 中文
	AN-1837: Application Note 1837 LM2738 Evaluation Board	799 Kbytes	10-Apr-08
	AN-1350: Application Note 1350 LM2734 Evaluation Board	639 Kbytes	4-Feb-05
	AN-1418: Application Note 1418 LM2736 Evaluation Board	858 Kbytes	26-Oct-05	中文
	AN-1408: Application Note 1408 Designing Power Over Ethernet Using LM5070 and DP83865	1072 Kbytes	10-Jan-06	中文
	AN-1822: Application Note 1822 LMH6733 High Definition Video Transmission Over CAT5	691 Kbytes	14-Jan-09

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Standard Pack Size
LM2731XMF/NOPB LM2731XMF RoHS Status	SOT-23	Full production Lead Time: 8 weeks	Distributor Region Qty ARROW Worldwide 3000 AVNET-EM Worldwide 1859 DIGIKEY Worldwide 8903 FUTURE Worldwide 1100 NEWARK Americas 1696 RS COMPONENTS Worldwide 157	$1.08 each at 1K+ pcs	reel of 1000
LM2731XMFX/NOPB LM2731XMFX RoHS Status	SOT-23	Full production Lead Time: 6 weeks	Distributor Region Qty AITG Asia Pacific 1001 DIGIKEY Worldwide 0	$1.08 each at 1K+ pcs	reel of 3000
LM2731YMF/NOPB LM2731YMF RoHS Status	SOT-23	Full production Lead Time: 6 weeks	Distributor Region Qty ARROW Worldwide 1644 AVNET-EM Worldwide 3000 BRITESTONE South Korea 2000 DIGIKEY Worldwide 4243 FUTURE Worldwide 1100 NEWARK Americas 424 RS COMPONENTS Worldwide 55 TECHMOSA Asia Pacific 5000	$1.08 each at 1K+ pcs	reel of 1000
LM2731YMFX/NOPB LM2731YMFX RoHS Status	SOT-23	Full production Lead Time: 6 weeks	Distributor Region Qty DIGIKEY Worldwide 0	$1.08 each at 1K+ pcs	reel of 3000

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
LM2731XMF/NOPB LM2731XMF		SOT-23	5	1 1	260 260	Detail	Download	N/A	S51A XTT
LM2731XMFX/NOPB LM2731XMFX		SOT-23	5	1 1	260 260	Detail	Download	N/A	S51A XTT
LM2731YMF/NOPB LM2731YMF		SOT-23	5	1 1	260 260	Detail	Download	N/A	S51B XTT
LM2731YMFX/NOPB LM2731YMFX		SOT-23	5	1 1	260 260	Detail	Download	N/A	S51B XTT

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 - Methods and Features of LED Drivers

CAD Symbols and Models Download LM2731 CAD Symbols

Models N/A

LM2731X   2.70 <= V in Lower  V   <= V in Upper  V   <= 14.00 V out 1.23 <=  V <= 22.00 I out    A <= 1.80 Ambient Temperature  °C <= 100 What are WEBENCH® tools?

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM2731XMF	ABCD150	0	34175	0	0	4234000	1	1201409060
LM2731XMFX	ABCD150	0	34175	0	0	4234000	1	1201409060
LM2731YMF	ABCD150	0	34175	0	0	4234000	1	1201409060
LM2731YMFX	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.