LM3530 Datasheet, PDF (1/50 Pages) National Semiconductor (TI) – High Efficiency White LED Driver with Programmable Ambient Light Sensing Capability and I2C Compatible Interface

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LM3530
SNVS606L – JUNE 2009 – REVISED DECEMBER 2014
LM3530 High-Efficiency White-LED Driver with Programmable Ambient Light Sensing
Capability and I²C-Compatible Interface
1 Features
•1 Drives up to 11 LEDs in series
• 1000:1 Dimming Ratio
• 90% Efficient
• Programmable Dual Ambient Light Sensor Inputs
with Internal ALS Voltage Setting Resistors
• I²C Programmable Logarithmic or Linear
Brightness Control
• External PWM Input for Simple Brightness
Adjustment
• True Shutdown Isolation for LEDs and Ambient
Light Sensors
• Internal Soft-Start Limits Inrush Current
• Wide 2.7-V to 5.5-V Input Voltage Range
• 40-V and 25-V Overvoltage Protection Options
• 500-kHz Fixed Frequency Operation
• 839-mA Peak Current Limit
2 Applications
• Smartphone LCD Backlighting
• Personal Navigation LCD Backlighting
• 2 to 11 Series White-LED Backlit Display Power
Source
space
3 Description
The LM3530 current mode boost converter supplies
the power and controls the current in up to 11 series
white LEDs. The 839-mA current limit and 2.7-V to
5.5-V input voltage range make the device a versatile
backlight power source ideal for operation in portable
applications.
The LED current is adjustable from 0 mA to 29.5 mA
via an I²C-compatible interface. The 127 different
current steps and 8 different maximum LED current
levels give over 1000 programmable LED current
levels. Additionally, PWM brightness control is
possible through an external logic level input.
The device also 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 voltage setting
resistors which can be made high impedance to
reduce power during shutdown. The 500-kHz
switching frequency allows for high converter
efficiency over a wide output voltage range
accommodating from 2 to 11 series LEDs. Finally, the
support of Content Adjusted Backlighting maximizes
battery life while maintaining display image quality.
The LM3530 operates over the −40°C to 85°C
temperature range.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (MAX)
LM3530
DSBGA (12)
1.64 mm x 1.24 mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
Simplified Schematic
2.7V to 5.5V
L
D1
VLOGIC
C _IN
10 k: 10 k: 10 k: 10 k:
VIN
Ambient Light
Sensor
SW
IN
LM3530
SCL
OVP
SDA
HWEN
INT
PWM
ILED
ALS1
GND
ALS2
Up to 40V
COUT
VIN
Ambient Light
Sensor
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.