Features • Drives 4 Individual Common-Anode LEDs with up to 20mA each for a Main Display Backlight • Drives 3 Individual Common-Cathode LEDs with up to 20mA each for a Sub-Display Backlight • Independent Resistor-Programmable Current Setting • Excellent Current and Brightness Matching • High-Efficiency 3/2x Charge Pump • Extended Li-Ion Input: 2.7V to 5.5V • PWM Brightness Control: 100Hz - 1kHz • 18-bump Thin Micro SMD Package: (2.1mm x 2.4mm x 0.6mm) Description The LM27961 is a charge-pump-based white-LED driver that is ideal for mobile phone display backlighting. It is intended to drive 4 LEDs for a main phone display backlight and 3 LEDs for a sub-display backlight. Regulated internal current sources deliver excellent current and brightness matching in all LEDs. The LED driver current sources are split into two independently controlled groups. The primary group (Group A) can be used to backlight a main phone display with up to 4 LEDs. The low-side current drivers of Group A accommodate common-anode-type LEDs. The second group (Group B) can backlight a secondary display with up to 3 LEDs. The high-side current drivers of Group B accommodate common-cathode-type LEDs. Both Group A and Group B can also drive standard two-terminal LEDs, and provide other general lighting functions (keypad lighting, fun lighting, etc). The brightness of the two LED groups can be adjusted independently with external resistors. The LM27961 works off an extended Li-Ion input voltage range (2.7V to 5.5V). Voltage boost is achieved with a high-efficiency 3/2×-gain charge pump. The LM27961 is available in National's chip-scale 18-bump micro SMD package. Applications • Mobile Phone Display Lighting • Mobile Phone Keypad Lighting • PDAs • General LED Lighting

Also Recommended LM2796▲ 7 High Side LED Outputs LP3936 6 White LED And 1 RGB Drivers With Inductive Boost LM2794▲ 4 LED Outputs With Active-Low Shutdown Pin LM2795▲ 4 LED Outputs With Active-High Shutdown Pin LM27953▲ 4 Lowside LED Outputs LM3570▲ 3 LED Outputs With Regulated Charge Pump LP3933 6 White LED And 2 RGB Drivers With Inductive Boost 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
	LM27961 Dual-Display White LED Driver with 3/2x Switched Capacitor Boost	711 Kbytes	18-Nov-04

Featured Application Notes

Title		Size	Date	Other Language
	AN-1362: Application Note 1362 LM27961- Dual-Display White LED Driver with 3/2x Switched Capacitor Boost	625 Kbytes	30-Jun-05	中文

More Application Notes

Title		Size	Date	Other Language
	AN-1321: Application Note 1321 LM2796 Evaluation Board	453 Kbytes	25-May-04
	AN-1582: Application Note 1582 LM27965 Dual Display White LED Driver with I2C Compatible Brightness Control	1226 Kbytes	18-Mar-07	中文

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Standard Pack Size
LM27961TL/NOPB RoHS		Lifetime buy Lead Time: 6 weeks	Distributor Region Qty DIGIKEY Worldwide 0 FARNELL Europe and Asia 245	$1.50 each at 1K+ pcs	reel of 250
LM27961TLX/NOPB RoHS		Lifetime buy Lead Time: 6 weeks	Distributor Region Qty DIGIKEY Worldwide 0	$1.50 each at 1K+ pcs	reel of 3000

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM27961TL	LM2756	National Semiconductor	30 Nov 2009
LM27961TLX	LM2756	National Semiconductor	30 Nov 2009

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM27961TL	CS065	2	38968	52	0	4402000	1	1249079519
LM27961TLX	CS065	2	38968	52	0	4402000	1	1249079519

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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Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM27961TL	LM2756	National Semiconductor	30 Nov 2009
LM27961TLX	LM2756	National Semiconductor	30 Nov 2009