1FEATURES

2Lighting:

• 6-channel Backlight Capability

• Internal ALS Engine; PWM Input to Support

CABC

• Built-in Power Supply and Gain Control for

Ambient Light Sensor

• Up to 90% Efficiency

• Adaptive Charge Pump with 1x and 1.5x Gains

for Maximum Efficiency

• 128 Dimming Steps for Group A, Exponential

or Linear Dimming Selectable by Register

Setup

• 8 Linear Dimming States for Group B

LDOs:

• 4 Programmable LDOs (300mA/150mA Output

Currents)

• Default Startup Voltage States

• Low Dropout Voltage: 100mV typ. at 150mA

Load Current

• LDO Input Voltage = 1.8V to VIN_A

• Overload Protection

Combined Common Features:

• Wide Input Voltage Range: 2.7V to 5.5V

• I2C-compatible Serial Interface

• 2 General-purpose Outputs

APPLICATIONS

• Smartphone Lighting

• MP3 players, Gaming Devices

• Digital Cameras

DESCRIPTION

The LM3538 is a highly integrated LED driver

capable of driving 6 LEDs in parallel for single display

backlighting applications. Independent LED control

allows for a subset of the main display LEDs to be

selected for partial illumination applications.

I2C-compatible control allows full configurability of the

backlighting function. The LM3538 provides multi-

zone Ambient Light Sensing allowing autonomous

backlight intensity control in the event of changing

ambient light conditions. A PWM input is also provided to give the user a means to adjust the

backlight intensity dynamically based upon the

content of the display.

Four integrated LDOs are fully configurable through

I2C capable of addressing point-of-load regulation

needs for functions such as integrated camera

modules. The LDOs can be powered from main

battery source, or by a fixed output voltage of an external buck converter (post regulation) leading to

higher conversion efficiency.

The LM3538 provides excellent efficiency without the

use of an inductor by operating the charge pump in a

gain of 3/2 or in Pass-Mode. The proper gain for

maintaining current regulation is chosen, based on

LED forward voltage, so that efficiency is maximized

over the input voltage range

LM3538 is offered in a tiny 30-bump DSBGA

package.