LM3533 Datasheet, PDF (1/53 Pages) Texas Instruments – Complete Lighting Power Solution for Smartphone Handsets

LM3533
Complete Lighting Power Solution for Smartphone Handsets
General Description
The LM3533 is a complete power source for backlight, key-
pad, and indicator LEDs in smartphone handsets. The high-
voltage inductive boost converter provides the power for two
series LED strings for display backlight and keypad functions
(HVLED1 and HVLED2). The integrated charge pump pro-
vides the bias for the five low-voltage indicator LED current
sinks (LVLED1-LVLED5). All low-voltage current sinks can
have a programmable pattern modulated onto their output
current for a wide variety of blinking patterns.
Additional features include a Pulse Width Modulation (PWM)
control input for content adjustable backlight control, and an
Ambient Light Sensor interface (ALS) with an internal 8-bit
ADC to provide automatic current adjustment based upon
ambient light conditions. Both the PWM and ALS inputs can
be used to control any high- or low-voltage current sink.
The LM3533 is fully programmable via an I²C-compatible in-
terface. The device is available in a 20-bump (1.755mm x
2.015mm x 0.6mm) micro SMD and operates over a 2.7V to
5.5V input voltage range and a −40°C to +85°C temperature
range.
Features
● ^{Drives Two Parallel High-Voltage LED Strings for Display}
and Keypad Lighting
● ^{High-Voltage Strings Capable of up to 40V Output Voltage}
and up to 90% Efficiency
● ^{Up to 30mA per Current Sink (Both Backlight and}
Indicator)
● ^{14-Bit Equivalent Exponential Dimming with 8-Bit}
Programmable Backlight Code
● ^{Selectable Analog ALS Input with 128 Programmable Gain}
Setting Resistors or PWM ALS Input with Internal Low
Pass Filter
● ^{PWM Input for Content Adjustable Brightness Control}
(CABC)
● ^{Five Low-Voltage Current Sinks for Indicator LEDs}
● ^{Integrated Charge Pump for Improved Efficiency and VIN}
Operating Range
● ^{Internal Pattern Generation Engine}
● ^{Fully Configurable LED Grouping and Control}
● ^{Four Programmable Over-voltage Protection Thresholds}
(16V, 24V, 32V, and 40V)
● ^{Programmable 500kHz and 1MHz Switching Frequency}
● ^{27mm2 Total Solution Size}
Applications
● ^{Power Source for Smart Phone Illumination}
● ^{Display, Keypad and Indicator Illumination}
● ^{RGB Indicator Driver}
TYPICAL APPLICATION CIRCUIT
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.
301357 SNOSC68A
30135701
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