Four-String, White LED Driver for LCD Backlight Applications Data Sheet ADD5211 FEATURES GENERAL DESCRIPTION White LED driver based on an inductive boost controller The ADD5211 is a four-string, white LED driver for backlight Wide input voltage range: 4.5 V to 40 V applications based on high efficiency, current mode, step-up Adaptive output voltage to minimize power dissipation converter technology. The boost controller drives an external Adjustable operating frequency: 200 kHz to 1.2 MHz MOSFET switch for step-up regulation from an input voltage Programmable UVLO of 4.5 V to 40 V and a pin adjustable operating frequency from Programmable soft start time for boost converter 200 kHz to 1.2 MHz. An adjustable UVLO function is implemented Programmable external MOSFET switching rising/falling time to reduce input current during power-off. Drives up to 4 LED current sinks with internal MOSFETs The ADD5211 provides four regulated current sinks for uniform Brightness control with PWM input brightness intensity. Each current sink can be driven from 40 mA Adjustable LED current: 40 mA to 200 mA to 200 mA the LED driving current is pin adjustable using an Headroom control to maximize efficiency external resistor. With an input PWM interface, the ADD5211 LED dimming frequency: up to 25 kHz drives up to four parallel strings of multiple series connected LEDs. PWM dimming at 300 Hz: 1000:1 Additional features include LED short protection, LED open Open-drain fault indicator protection, boost output short protection, overvoltage protection, LED open and LED short fault protection cycle-by-cycle current limit, and thermal shutdown for both the Thermal shutdown IC and the LED array. An open-drain fault output is also included. Undervoltage lockout (UVLO) A programmable soft start is implemented to reduce inrush 24-lead, 4 mm 4 mm LFCSP current during startup. APPLICATIONS LCD monitor and TV LED backlights Industrial lighting APPLICATION CIRCUIT + VIN UVLO VIN GATE P GATE N VDR CS RAMP EN OFF ON PGND PWM OVP ADD5211 FAULT VDD FB4 FB3 FB2 LSD FB1 ISET LGND AGND FREQ COMP SS Figure 1. Rev. A Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 20132017 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. 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Technical Support www.analog.com 10555-001ADD5211 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Pin Configuration and Function Descriptions ..............................7 Applications ....................................................................................... 1 Typical Performance Characteristics ..............................................8 General Description ......................................................................... 1 Theory of Operation ...................................................................... 10 Application Circuit ........................................................................... 1 Current Mode, Step-Up Switching Controller ....................... 10 Revision History ............................................................................... 2 LED Current Regulation ........................................................... 11 Detailed Functional Block Diagram .............................................. 3 Fault Protection .......................................................................... 12 Specifications ..................................................................................... 4 Applications Information .............................................................. 14 General Specifications ................................................................. 4 Layout Guidelines....................................................................... 14 Step-Up Switching Controller Specifications ........................... 5 Boost Component Selection ..................................................... 14 LED Current Regulation Specifications .................................... 5 Typical Application Circuits ......................................................... 17 Absolute Maximum Ratings ............................................................ 6 Outline Dimensions ....................................................................... 18 Thermal Resistance ...................................................................... 6 Ordering Guide .......................................................................... 18 ESD Caution .................................................................................. 6 REVISION HISTORY 10/2017Rev. 0 to Rev. A Changed CP-24-7 to CP-24-15 .................................... Throughout Change to Operating Temperature Range (T ), Table 4 ............. 6 A Updated Outline Dimensions ....................................................... 18 Changes to Ordering Guide .......................................................... 18 10/2013Revision 0: Initial Version Rev. A Page 2 of 20