Features • Drives 4 Individual Common-Anode LEDs with up to 20mA each for a Main 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 LM27953 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. Regulated internal current sources deliver excellent current and brightness matching in all LEDs. The LED driver current sinks can be used to backlight a main phone display with up to 4 LEDs. The low-side current drivers accommodate common-anode-type LEDs. The current sinks can also drive standard two-terminal LEDs, and provide other general lighting functions (keypad lighting, fun lighting, etc). The brightness of the LEDs can be adjusted independently with an external resistor. The LM27953 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 LM27953 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▲ Drives 7 LEDs LP3936 6 White LED And 1 RGB Driver With Inductive Boost LM2794▲ Drives 4 LEDs, With Active-Low Shutdown Pin LM2795▲ Drives 4 LEDs, With Active-High Shutdown Pin LM3570▲ Drives 3 LEDs 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
	LM27953 White LED Driver with Four LED Current Sinks and 3/2x Switched Capacitor Boost	681 Kbytes	18-Nov-04	日本語

Featured Application Notes

Title		Size	Date	Other Language
	AN-1251: Application Note 1251 Switched Capacitor Circuits Provide Efficient and Functional White LED Drive	55 Kbytes	26-Sep-02
	AN-1218: Application Note 1218 LM2791/2/4/5 Evaluation Board	424 Kbytes	13-May-04

More Application Notes

Title		Size	Date	Other Language
	AN-1218: Application Note 1218 LM2791/2/4/5 Evaluation Board	424 Kbytes	13-May-04
	AN-1251: Application Note 1251 Switched Capacitor Circuits Provide Efficient and Functional White LED Drive	55 Kbytes	26-Sep-02

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Standard Pack Size
LM27953TL/NOPB RoHS		Lifetime buy Lead Time: 6 weeks	Distributor Region Qty DIGIKEY Worldwide 236 FARNELL Europe and Asia 492	$1.20 each at 1K+ pcs	reel of 250
LM27953TLX/NOPB RoHS		Lifetime buy Lead Time: 6 weeks	Distributor Region Qty DIGIKEY Worldwide 0	$1.20 each at 1K+ pcs	reel of 3000

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM27953TL	LM2796	National Semiconductor	30 Nov 2009
LM27953TLX	LM2796	National Semiconductor	30 Nov 2009

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM27953TL	CS065	2	38968	52	0	4402000	1	1249079519
LM27953TLX	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.

For more information on Reliability Metrics, please click here.

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM27953TL	LM2796	National Semiconductor	30 Nov 2009
LM27953TLX	LM2796	National Semiconductor	30 Nov 2009