Features Output matching of ± 0.3% Drives up to two LED's 3V to 5.8V Input Voltage Up to 36mA output current Soft start limits inrush current Analog brightness control Separate shutdown input Very small solution size - no inductor 0.7mA typical operating current 1µA (max.) shutdown current 450kHz switching frequency (min.) Linear regulation generates predictable noise spectrum LLP-10 package: 3mm X 3mm X 0.8mm Description The LM2791 is a CMOS charge-pump voltage doubler and regulator that provides two regulated current sources. The LM2791 is designed to drive two white (or blue) LEDs with matched currents (within ± 0.3%) to produce balanced light sources for display backlights. They accept an input voltage range from 3V to 5.8V and maintain a constant current determined by an external set resistor. The LM2791 delivers up to 36mA of load current to accommodate two high forward voltage (typically white) LEDs. The switching frequency is 450kHz (min.) to keep the conducted noise spectrum away from sensitive frequencies within portable RF devices. In the LM2791, brightness is controlled by applying a voltage between GND and 3.0V to the BRGT pin. The LM2791 is available in active high or low shutdown versions. The shutdown pin reduces the operating current to 1µA (max.). The LM2791 is available in a 10 pin leadless leadframe (LLP) CSP package. Applications White LED Display Backlights White LED Keypad Backlights 1-Cell Li-Ion battery-operated equipment including PDAs, hand-held PCs, cellular phones Flat Panel Dispalys

Also Recommended LM27966▲ Advanced Brightness Control With 12C Interface, Higher Efficiency With Adaptive Gain Charge Pump LM2792▲ Dual LED Driver With 900KHz Switching Frequency LM2793▲ High-Efficiency Dual LED Driver With 3/2 Gain Charge Pump LM2794▲ High-Efficiency Quad LED Driver With 3/2 Gain Charge Pump, Active Low Shutdown Pin LM2795▲ High-Efficiency Quad LED Driver With 3/2 Gain Charge Pump, Active High Shutdown Pin

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

Datasheets

Title		Size	Date	Other Language
	LM2791 Current Regulated Switched Capacitor LED Driver with Analog Brightness Control	226 Kbytes	30-Jul-02

Application Notes

Title		Size	Date	Other Language
	AN-1218: Application Note 1218 LM2791/2/4/5 Evaluation Board	424 Kbytes	13-May-04

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LM2791LD-L/NOPB LM2791LD-L RoHS Status	LLP	Full production Lead Time: 6 weeks	Distributor Region Qty DIGI-KEY Worldwide 0	$0.75 each at 1K+ pcs	reel of 1000

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM2791LD-H	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM2791LDX-L	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009

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 LM2791.

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 LM2791 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
LM2791LD-L/NOPB LM2791LD-L	20.523 20.595	LLP	10	3 1	260 235	Detail	Download	N/A	ZXYTT SNB

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 LM2791.

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 LM2791 is located at RoHS Status.

CAD Symbols and Models Download LM2791 CAD Symbols

Models N/A

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM2791LD-L	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 LM2791.

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 LM2791 is located at RoHS Status.

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM2791LD-H	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM2791LDX-L	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009