LT3755/LT3755-1/LT3755-2 40V , 75V LED Controllers IN OUT Fae Tseru Dpircse Tnoi n 3000:1 True Color PWM Dimming The LT 3755, LT3755-1 and LT3755-2 are DC/DC control- n Wide Input Voltage Range: 4.5V to 40V lers designed to operate as a constant-current source for n Output Voltage Up to 75V driving high current LEDs. They drive a low side external n Constant-Current and Constant-Voltage Regulation N-channel power MOSFET from an internal regulated 7.15V n 100mV High Side Current Sense supply. The fixed frequency, current mode architecture n Drives LEDs in Boost, Buck Mode, Buck-Boost Mode, results in stable operation over a wide range of supply SEPIC or Flyback Topology and output voltages. A ground referenced voltage FB pin n Adjustable Frequency: 100kHz to 1MHz serves as the input for several LED protection features, n Open LED Protection and also makes it possible for the converter to operate n Programmable Undervoltage Lockout with Hysteresis as a constant-voltage source. A frequency adjust pin n Improved Open LED Status Pin (LT3755-2) allows the user to program the frequency from 100kHz n Frequency Synchronization (LT3755-1) to 1MHz to optimize efficiency, performance or external n PWM Disconnect Switch Driver component size. n CTRL Pin Provides Analog Dimming The LT3755/LT3755-1/LT3755-2 sense output current at n Low Shutdown Current: <1A the high side of the LED string. High side current sensing n Programmable Soft-Start is the most flexible scheme for driving LEDs, allowing n Thermally Enhanced 16-Lead QFN (3mm 3mm) boost, buck mode or buck-boost mode configuration. and MSOP Packages The PWM input provides LED dimming ratios of up to 3000:1, and the CTRL input provides additional analog a acilpp Tsnoi dimming capability. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear n High Power LED Technology Corporation. True Color PWM is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. n Battery Chargers Protected by U.S. Patents including 7199560, 7321203. n Accurate Current Limited Voltage Regulators T lacipy a acilpp Tnoi 50W White Automotive LED Headlamp Driver Efficiency vs V IN 22H V IN 100 8V TO 40V 1M 4.7F 4.7F 1M V IN SHDN/UVLO FB 96 V REF ISP 23.7k 185k 332k LT3755-2 0.1 1A 92 CTRL ISN INTV CC 40.2k GATE 88 100k SENSE OPENLED 0.015 50W PWM LED 84 SS STRING PWMOUT RT V GND INTV C CC 80 28.7k 0.01F 0 10 20 30 40 375kHz 10k 4.7F V (V) IN 0.001F 37551 TA01b 37551 TA01a 37551fd EFFICIENCY (%)LT3755/LT3755-1/LT3755-2 (Note 1) a ulosb T e Mixa Mu M r a Tsgni V ............................................................................40V RT ............................................................................1.5V IN SHDN/UVLO (Note 3) ................................................40V SENSE ......................................................................0.5V ISP, ISN .....................................................................75V Operating Junction Temperature Range (Notes 2, 5) INTV ......................................................V + 0.3V, 8V LT3755E/LT3755I ...............................40C to 125C CC IN GATE, PWMOUT (Note 4) ......................... INTV + 0.3V LT3755H ...........................................40C TO 150C CC CTRL, PWM, OPENLED .............................................12V Storage Temperature Range ...................65C to 150C V , V , SS, FB ..........................................................3V Lead Temperature (Soldering, 10 sec) C REF SYNC ..........................................................................8V MSOP ............................................................... 300C p ni c no Farugi Tnoi TOP VIEW 16 15 14 13 TOP VIEW V 1 12 FB REF PWMOUT 1 16 GATE FB 2 15 SENSE PWM 2 11 PWMOUT 17 3 ISN 14 V IN GND SYNC OR OPENLED 3 10 GATE ISP 4 17 13 INTV CC 5 VC GND 12 SHDN/UVLO SS 4 9 SENSE CTRL 6 11 RT 7 V 10 SS 5 6 7 8 REF PWM 8 9 SYNC OR OPENLED MSE PACKAGE 16-LEAD PLASTIC MSOP T = 125C (E, I GRADES), T = 150C (H GRADE), = 43C/W, = 4C/W JMAX JMAX JA JC EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB UD PACKAGE 16-LEAD (3mm 3mm) PLASTIC QFNs T = 125C, = 68C/W, = 4.2C/W JMAX JA JC EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB ro D re ni Fro Ma Tnoi LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT3755EUD PBF LT3755EUD TRPBF LDGC 40C to 125C 16-Lead (3mm 3mm) Plastic QFN LT3755IUD PBF LT3755IUD TRPBF LDGC 40C to 125C 16-Lead (3mm 3mm) Plastic QFN LT3755EUD-1 PBF LT3755EUD-1 TRPBF LDMS 40C to 125C 16-Lead (3mm 3mm) Plastic QFN LT3755IUD-1 PBF LT3755IUD-1 TRPBF LDMS 40C to 125C 16-Lead (3mm 3mm) Plastic QFN LT3755EUD-2 PBF LT3755EUD-2 TRPBF LFJZ 40C to 125C 16-Lead (3mm 3mm) Plastic QFN LT3755IUD-2 PBF LT3755IUD-2 TRPBF LFJZ 40C to 125C 16-Lead (3mm 3mm) Plastic QFN LT3755EMSE PBF LT3755EMSE TRPBF 3755 16-Lead Plastic MSOP 40C to 125C LT3755IMSE PBF LT3755IMSE TRPBF 3755 16-Lead Plastic MSOP 40C to 125C LT3755EMSE-1 PBF LT3755EMSE-1 TRPBF 37551 16-Lead Plastic MSOP 40C to 125C LT3755IMSE-1 PBF LT3755IMSE-1 TRPBF 37551 16-Lead Plastic MSOP 40C to 125C LT3755EMSE-2 PBF LT3755EMSE-2 TRPBF 37552 16-Lead Plastic MSOP 40C to 125C LT3755IMSE-2 PBF LT3755IMSE-2 TRPBF 37552 16-Lead Plastic MSOP 40C to 125C LT3755HMSE-2 PBF LT3755HMSE-2 TRPBF 37552 16-Lead Plastic MSOP 40C to 150C Consult LTC Marketing for parts speciefi d with wider operating temperature ranges. *The temperature grade is identiefi d by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: