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 LM3570▲ 3 LED Outputs With Regulated Charge Pump LP3933 6 White LED And 2 RGB Drivers With Inductive Boost LM27953▲ 4 Lowside LED Outputs

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

Datasheets

Title		Size	Date	Other Language
	LM27961 Dual-Display White LED Driver with 3/2x Switched Capacitor Boost	711 Kbytes	18-Nov-04

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

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Pack Size

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

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 LM27961.

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 LM27961 is located at RoHS Status.

Part Number(s) (NSID)	Description	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LM27961TLEV	Dual-Display White LED Driver with 3/2x Switched Capacitor Boost	Full production	Distributor Region Qty DIGI-KEY Worldwide 0	$85.00 each	1
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 LM27961 works off an extended Li-Ion input voltage range (2.7V to 5.5V). Voltage boost is achieved with a high-efficiency 3/2x-gain charge pump. The LM27961 is available in National's chip-scale 18-bump micro SMD package. 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) Applications: Mobile Phone Display Lighting Mobile Phone Keypad Lighting PDAs General LED Lighting

National Semiconductor follows the provisions of the Product Stewardship Guide for Customers (CSP-9-111C1) and Banned Substances and Materials of Interest Specification (CSP-9-111S2) for regulatory environmental compliance. Details may be found at: www.national.com/en/packaging/greennopb.html. Lead free products are RoHS compliant.

Lead Free product status is available through the search tool located here

Part Number(s) (NSID)	Weight (milligrams)	Type	Pins	MSL Rating	Peak Reflow	RoHS Status	CAD Symbols	Models	Package Marking Format

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 LM27961.

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 LM27961 is located at RoHS Status.

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