LT3517 Full-Featured LED Driver with 1.5A Switch Current Features Description n 5000:1 True Color PWM Dimming Ratio The LT 3517 is a current mode DC/DC converter with an n 1.5A, 45V Internal Switch internal 1.5A, 45V switch specifically designed to drive n 100mV High Side Current Sense LEDs. The LT3517 operates as a LED driver in boost, n Open LED Protection buck mode and buck-boost mode. It combines a tradi- n Adjustable Frequency: 250kHz to 2.5MHz tional voltage loop and a unique current loop to operate n Wide Input Voltage Range: as a constant-current source or constant-voltage source. n Operation from 3V to 30V Programmable switching frequency allows optimization of n Transient Protection to 40V the external components for efficiency or component size. n Operates in Boost, Buck Mode and Buck-Boost Mode The switching frequency of LT3517 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 up to 5000:1 LED dimming. The CTRL n Low Shutdown Current: <1A pin provides further 10:1 dimming ratio. n Available in (4mm 4mm) 16-Lead QFN and 16-Pin The LT3517 is available in the tiny footprint 16-lead QFN TSSOP Packages (4mm 4mm) and the 16-pin TSSOP packages. The LT3517 provides a complete solution for both constant- a voltage and constant-current applications. n Display Backlighting L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks and True Color PWM is a trademark of Analog Devices, Inc. All other trademarks are the n Automotive and Avionic Lighting property of their respective owners. Protected by U.S. Patents, including 7199560, 7321203, 7746300. n Illumination n Scanners t ypical a 1A Buck Mode LED Driver Efficiency 100 CTRL = V REF 10F 100m PV IN 90 24V 2.2F 1A 80 15H ISP ISN TG V IN V SW 70 IN 3.3V SHDN 2.2F LT3517 60 V CTRL FB REF 50 PWM PWM SS SYNC RT 40 TGEN V VC GND REF 0 20 40 60 80 100 16.9k PWM DUTY CYCLE (%) 0.1F 1MHz 0.1F 3517 TA01b 3517 TA01a 3517fh 1 For more information www.linear.com/LT3517 EFFICIENCY (%) pplication pplicationsLT3517 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) LT3517E .............................................40C to 125C LT3517I ..............................................40C to 125C LT3517H ............................................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 17 RT 4 13 ISP GND 17 V CTRL 3 10 IN SYNC 5 12 ISN SHDN 4 9 PWM 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, (PAD) = 10C/W JMAX JA JC EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB o r Der i n F M