LM27964

SCL

SDIO

D1A

GND

D2A

D3A

D4A

D2B

D1B

MAIN DISPLAY

SUB DISPLAY

KEYPAD LEDs

DKEY

I

2

C Compatible

Interface

VIO

LM27964

www.ti.com

SNOSAL6D – MAY 2005 – REVISED MAY 2013

LM27964 White LED Driver System with I2C Compatible Brightness Control

Check for Samples: LM27964

1

FEATURES

APPLICATIONS

2

•

87% Peak LED Drive Efficiency

•

Mobile Phone Display Lighting

•

0.2% Current Matching between Current Sinks

•

Mobile Phone Keypad Lighting

•

Drives 6 LEDs with up to 30mA per LED in

•

PDAs Backlighting

Two Distinct Groups, for Backlighting Two

•

General LED Lighting

Displays (main LCD and sub LCD)

•

Dedicated Keypad LED Driver with up to 80mA

DESCRIPTION

of Drive Current

The LM27964 is a charge-pump-based white-LED

driver

that

is

ideal

for

mobile

phone

display

•

Independent Resistor-Programmable Current

backlighting. The LM27964 can drive up to 6 LEDs in

Settings

parallel along with multiple keypad LEDs, with a total

•

output current up to 180mA. Regulated internal

•

Adaptive 1×- 3/2× Charge Pump

current sources deliver excellent current matching in

all LEDs.

•

Extended Li-Ion Input: 2.7V to 5.5V

•

Small Low Profile Industry Standard Leadless

The LED driver current sources are split into two

independently controlled groups. The primary group

Package, WQFN-24 : (4mm x 4mm x 0.8mm)

(4 LEDs) can be used to backlight the main phone

•

LM27964SQ-I LED PWM Frequency = 10kHz,

display and the second group (2 LEDs) can be used

LM27964SQ-C LED PWM frequency = 23kHz

to backlight a secondary display. A single Keypad

LED driver can power up to 16 keypad LEDs with a

compatible

interface

that

allows

the

user

to

independently control the brightness on each bank of

LEDs.

Typical Application Circuit

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

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PRODUCTION DATA information is current as of publication date.

Copyright © 2005–2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.