LM3538_13 Datasheet, PDF (1/31 Pages) Texas Instruments – 6-Channel WLED Driver with Four Integrated LDOs

LM3538
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SNVS674A – JUNE 2011 – REVISED MAY 2013
LM3538 6-Channel WLED Driver with Four Integrated LDOs
Check for Samples: LM3538
FEATURES
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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 V_{IN_A}
• Overload Protection
Combined Common Features:
• Wide Input Voltage Range: 2.7V to 5.5V
• I²C-compatible Serial Interface
• 2 General-purpose Outputs
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.
APPLICATIONS
• Smartphone Lighting
• MP3 players, Gaming Devices
• Digital Cameras
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2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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