LM3532_13 Datasheet, PDF (1/47 Pages) Texas Instruments – LM3532 High Efficiency White LED Driver with Programmable Ambient Light Sensing Capability and I2C-Compatible Interface

LM3532
www.ti.com
SNVS653D – JULY 2011 – REVISED JUNE 2013
LM3532 High Efficiency White LED Driver with Programmable Ambient Light Sensing
Capability and I²C-Compatible Interface
Check for Samples: LM3532
FEATURES
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•2 Drives up to 3 Parallel High-Voltage LED
Strings at 40V Each with up to 90% Efficiency
• 0.4% Typical Current Matching Between
Strings
• 256 Level Logarithmic and Linear Brightness
Control with 14-Bit Equivalent Dimming
• I²C-compatible Interface
• Direct Read Back of Ambient Light Sensor via
8-bit ADC
• Programmable Dual Ambient Light Sensor
Inputs with Internal Sensor Gain Selection
• Dual External PWM Inputs for LED Brightness
Adjustment
• Independent Current String Brightness Control
• Programmable LED Current Ramp Rates
• 40V Over-Voltage Protection
• 1A Typical Current Limit
APPLICATIONS
• Power Source for White LED Backlit LCD
Displays
• Programmable Keypad Backlight
DESCRIPTION
The LM3532 is a 500 kHz fixed frequency
asynchronous boost converter which provides the
power for 3 high-voltage, low-side current sinks. The
device is programmable over an I²C-compatible
interface and has independent current control for all
three channels. The adaptive current regulation
method allows for different LED currents in each
current sink thus allowing for a wide variety of
backlight + keypad applications.
The main features of the LM3532 include dual
ambient light sensor inputs each with 32 internal
voltage setting resistors, 8-bit logarithmic and linear
brightness control, dual external PWM brightness
control inputs, and up to 1000:1 dimming ratio with
programmable fade in and fade out settings.
The LM3532 is available in a 16-bump, 0.4mm pitch
thin DSBGA (1.745 mm x 1.845 mm x 0.6 mm). The
device operates over a 2.7V to 5.5V input voltage
range and the −40°C to +85°C temperature range.
Typical Application Circuit
L
VIN
CIN
D1
VOUT up to 40V
COUT
VALS
Ambient Light
Sensor 1
VIN
IN
SW
OVP
Ambient Light
Sensor 2
ALS1
ALS2
SDA
LM3532
SCL
HWEN
INT
T0
ILED1
ILED2
ILED3
PWM1
PWM2
PGND
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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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