LT3517 Full-Featured LED Driver with 1.5A Switch Current FeaturesDescription n 5000:1True 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: <1µA 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 applications LT3517 provides a complete solution for both constant- 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 typical application1A Buck Mode LED DriverEfficiency 100 10µF CTRL = VREF 100mΩ PVIN 90 24V 2.2µF 1A 15µH 80 ISP ISN TG VIN VIN SW 3.3V 70 2.2µF SHDN LT3517 EFFICIENCY (%) 60 VREF CTRL FB PWM PWM SS 50 SYNC RT TGEN V 40 REF VC GND 0 20 40 60 80 100 16.9k 0.1µF PWM DUTY CYCLE (%) 0.1µF 1MHz 3517 TA01b 3517 TA01a 3517fh For more information www.linear.com/LT3517 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 Related Parts
