Features Input power from 2.2V to 16V Output voltage adjustable down to 0.6V Power Good flag, adjustable soft-start and output enable for easy power sequencing Output over-voltage and under-voltage latch-off (LM2727) Output over-voltage and under-voltage flag (LM2737) Reference Accuracy: 1.5% (0°C - 125°C) Current limit without sense resistor Soft start Switching frequency from 50 kHz to 2 MHz TSSOP-14 package Description The LM2727 and LM2737 are high-speed, synchronous, switching regulator controllers. They are intended to control currents of 0.7A to 20A with up to 95% conversion efficiencies. The LM2727 employs output over-voltage and under-voltage latch-off. For applications where latch-off is not desired, the LM2737 can be used. Power up and down sequencing is achieved with the power-good flag, adjustable soft-start and output enable features. The LM2737 and LM2737 operate from a low-current 5V bias and can convert from a 2.2V to 16V power rail. Both parts utilize a fixed-frequency, voltage-mode, PWM control architecture and the switching frequency is adjustable from 50kHz to 2MHz by adjusting the value of an external resistor. Current limit is achieved by monitoring the voltage drop across the on-resistance of the low-side MOSFET, which enhances low duty-cycle operation. The wide range of operating frequencies gives the power supply designer the flexibility to fine-tune component size, cost, noise and efficiency. The adaptive, non-overlapping MOSFET gate-drivers and high-side bootstrap structure helps to further maximize efficiency. The high-side power FET drain voltage can be from 2.2V to 16V and the output voltage is adjustable down to 0.6V. Applications Cable Modems Set-Top Boxes/ Home Gateways DDR Core Power High-Efficiency Distributed Power Local Regulation of Core Power

Also Recommended LM2647 Dual Channels, 28V Vin Max LM2727▲ Has Output Undervoltage And Output Overvoltage Latch-off LM2743▲ 3.0 To 6.0 Vcc LM2745▲ Has Clock Syncronization (Sync Pin) LM5115 75V Vin Sync Buck Controller

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

Datasheets

Title		Size	Date	Other Language
	LM2737 N-Channel FET Synchronous Buck Regulator Controller for Low Output Voltages	602 Kbytes	16-Jun-03	日本語

Application Notes

Title		Size	Date	Other Language
	AN-1325: Application Note 1325 LM2742 Evaluation Board	607 Kbytes	1-Apr-04
	AN-1247: Application Note 1247 LM2727 Evaluation Board	689 Kbytes	31-Oct-02

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LM2737MTC/NOPB LM2737MTC RoHS Status	TSSOP	Full production Lead Time: 6 weeks	Distributor Region Qty ARROW Worldwide 225 AVNET-EM Worldwide 896 DIGI-KEY Worldwide 267 FARNELL Europe and Asia 14 MOUSER Worldwide 366 RS COMPONENTS Worldwide 115 TAYLOR Americas 225 TECHMOSA Asia Pacific 846	$0.98 each at 1K+ pcs	rail of 94
LM2737MTCX/NOPB LM2737MTCX RoHS Status	TSSOP	Full production Lead Time: 6 weeks	Distributor Region Qty ARROW Worldwide 20000 AVNET-EM Worldwide 2500 DIGI-KEY Worldwide 0 MOUSER Worldwide 2500 TAYLOR Americas 20000 TECHMOSA Asia Pacific 5000	$0.98 each at 1K+ pcs	reel of 2500

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

Moisture Sensitivity Level Data for LM2737.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LM2737 is located at RoHS Status.

Part Number(s) (NSID)	Weight (milligrams)	Type	Pins	MSL Rating	Peak Reflow	RoHS Status	CAD Symbols	Models	Package Marking Format
LM2737MTC/NOPB LM2737MTC	53.783 54.004	TSSOP	14	1 1	260 260	Detail	Download	N/A	NSZXYTT 2737 MTC
LM2737MTCX/NOPB LM2737MTCX	53.783 54.004	TSSOP	14	1 1	260 260	Detail	Download	N/A	NSZXYTT 2737 MTC

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

Moisture Sensitivity Level Data for LM2737.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LM2737 is located at RoHS Status.

Reference Design

LM2737 Reference Design - 1 High Brightness LED, 2000 mA (Solar Cell)

CAD Symbols and Models Download LM2737 CAD Symbols

Models N/A

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM2737MTC	ABCD150	0	42680	0	0	6394000	1	1814314958
LM2737MTCX	ABCD150	0	42680	0	0	6394000	1	1814314958

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/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for LM2737.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LM2737 is located at RoHS Status.