LM3530 PRODUCT BRIEF

November 29, 2010

High Efficiency White LED Driver with Programmable

Interface

General Description

The LM3530 current mode boost converter supplies the pow-

er and controls the current in up to 11 series white LED’s. The

839mA current limit and 2.7V to 5.5V input voltage range,

makes the device a versatile backlight power source ideal for

operation in portable applications.

compatible interface. The 127 different current steps and 8

different maximum LED current levels give over 1000 pro-

grammable LED current levels. Additionally, PWM brightness

control is possible through an external logic level input.

Additionally, the device features two Ambient Light Sensor

inputs. These are designed to monitor analog output ambient

light sensors and provide programmable adjustment of the

LED current with changes in ambient light. Each ambient light

sensor input has independently programmable internal volt-

age setting resistors which can be made high impedance to

reduce power during shutdown. The LM3530's 500kHz

switching frequency allows for high converter efficiency over

a wide output voltage range accommodating from 2 to 11 se-

ries LEDs. Finally, the support of Content Adjusted Backlight-

ing maximizes battery life while maintaining display image

quality.

The LM3530 is available in a tiny 12-bump (1.6mm × 1.2mm

× 0.425mm) micro SMD package and operates over the -40°

C to +85°C temperature range.

Notice: This document is not a full datasheet. For more

imformation regarding this product, or to order samples,

please contact your National Semiconductor sales office

or visit http://www.national.com/support/dir.html.

Features

internal ALS Voltage Setting Resistors

Control

Sensors

Applications

LM3530 Layout Example

30086683

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