LT3518 Full-Featured LED Driver with 2.3A Switch Current Features Description n 3000:1 True 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 allows 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: <1A 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 and constant-current applications. a 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 t ypical a 1.5A Buck Mode LED Driver Efficiency 100 CTRL = V REF 10F 68m M1 90 PV IN 24V 2.2F 1.5A 80 15H ISP ISN TG V 70 IN V SW IN 3.3V SHDN 2.2F 60 LT3518 V REF CTRL FB 50 PWM PWM SS SYNC RT 40 TGEN V VC GND 0 20 40 60 80 100 REF PWM DUTY CYCLE (%) 16.9k 0.1F 1MHz 3518 TA01b 0.1F 3518 TA01a 3518ff 1 For more information www.linear.com/LT3518 EFFICIENCY (%) pplication pplicationsLT3518 a bsolute Maxi Mu M r (Note 1) V , SHDN, PWM, TGEN (Note 3) .............................40V Storage Temperature Range IN SW, ISP, ISN, TG .......................................................45V QFN .................................................... 65C to 150C TG Pin Below ISP Pin ................................................10V TSSOP ............................................... 65C to 150C FB, SYNC, SS, CTRL ...................................................6V Lead Temperature (Soldering, 10 sec) VC, RT, V ................................................................3V TSSOP ..............................................................300C REF Operating Junction Temperature Range (Notes 2, 4) LT3518E ............................................. 40C to 125C LT3518I .............................................. 40C to 125C LT3518H ............................................ 40C to 150C p in c F TOP VIEW TOP VIEW V 1 16 SW IN 16 15 14 13 SHDN 2 15 SW SW 1 12 FB V 3 14 TG REF SW 2 11 VC RT 4 13 ISP 17 17 V 3 10 CTRL IN GND SYNC 5 12 ISN SHDN PWM 4 9 SS 6 11 TGEN 5 6 7 8 PWM 7 10 FB CTRL 8 9 VC UF PACKAGE FE PACKAGE 16-LEAD (4mm 4mm) PLASTIC QFN 16-LEAD PLASTIC TSSOP T = 150C, = 36C/W JMAX JA T = 150C, = 40C/W, = 10C/W JMAX JA JC(PAD) EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB o r Der i n F M