LT3518 Full-Featured LED Driver with 2.3A Switch Current FeaturesDescription n 3000:1True Color PWM ™ Dimming Ratio The LT®3518 is a current mode DC/DC converter with an n 2.3A, 45V Internal Switch internal 2.3A, 45V switch specifically designed to drive n 100mV High Side Current Sense LEDs. The LT3518 operates as a LED driver in boost, buck n Open LED Protection mode and buck-boost mode. It combines a traditional n Adjustable Frequency: 250kHz to 2.5MHz voltage loop and a unique current loop to operate as a n Wide Input Voltage Range: constant-current source or constant-voltage source. Pro- n Operation from 3V to 30V grammable switching frequency al ows optimization of the n Transient Protection to 40V external components for efficiency or component size. The n Operates in Boost, Buck Mode and Buck-Boost Mode switching frequency of the LT3518 can be synchronized n Gate Driver for PMOS LED Disconnect to an external clock signal. The LED current is externally n Constant-Current and Constant-Voltage Regulation programmable with a 100mV sense resistor. The external n CTRL Pin Provides 10:1 Analog Dimming PWM input provides 3000:1 LED dimming. The CTRL pin n Low Shutdown Current: <1µA provides further 10:1 dimming ratio. n Available in (4mm × 4mm) 16-Lead QFN and 16-Pin The LT3518 is available in the tiny footprint 16-lead QFN TSSOP Packages (4mm × 4mm) and the 16-pin TSSOP package. The LT3518 provides a complete solution for both constant-voltage applications and constant-current applications. L, LT, LTC and LTM are registered trademarks and True Color PWM is a trademark of Analog n Display Backlighting Devices Inc. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 7199560, 7321203, 7746300. Patent Pending. n Automotive and Avionic Lighting n Illumination n Scanners typical application1.5A Buck Mode LED DriverEfficiency 100 CTRL = VREF 10µF 68mΩ M1 PVIN 90 24V 2.2µF 1.5A 80 15µH ISP ISN TG VIN 70 VIN SW 3.3V 2.2µF SHDN EFFICIENCY (%) LT3518 60 VREF CTRL FB 50 PWM PWM SS SYNC RT 40 TGEN VREF VC GND 0 20 40 60 80 100 16.9k PWM DUTY CYCLE (%) 0.1µF 0.1µF 1MHz 3518 TA01b 3518 TA01a 3518ff For more information www.linear.com/LT3518 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts