LT3755EMSE#TRPBF LT3755EMSE-2#TRPBF LT3755IMSE-2#TRPB LT3756EMSE-2#TRP Power Path Management IC LED Lighting Drivers 75V Full-Featured LE

FeaTures

n 3000:1 True Color PWMTM Dimming
n Wide Input Voltage Range: 4.5V to 40V
n Output Voltage Up to 75V
n Constant-Current and Constant-Voltage Regulation

n 100mV High Side Current Sense
n Drives LEDs in Boost, Buck Mode, Buck-Boost Mode, SEPIC or Flyback Topology
n Adjustable Frequency: 100kHz to 1MHz
n Open LED Protection
n Programmable Undervoltage Lockout with Hysteresis

n Improved Open LED Status Pin (LT3755-2)
n Frequency Synchronization (LT3755-1)
n PWM Disconnect Switch Driver
n CTRL Pin Provides Analog Dimming
n Low Shutdown Current: <1μA
n Programmable Soft-Start
n Thermally Enhanced 16-Lead QFN (3mm × 3mm) and MSOP Packages

ApplicaTions

n High Power LED
n Battery Chargers
n Accurate Current Limited Voltage Regulators

DescripTion

The LT®3755, LT3755-1 and LT3755-2 are DC/DC control- lers designed to operate as a constant-current source for driving high current LEDs. They drive a low side external N-channel power MOSFET from an internal regulated 7.15V supply. The xed frequency, current mode architecture results in stable operation over a wide range of supply and output voltages. A ground referenced voltage FB pin serves as the input for several LED protection features, and also makes it possible for the converter to operate as a constant-voltage source. A frequency adjust pin allows the user to program the frequency from 100kHz to 1MHz to optimize ef ciency, performance or external component size.

The LT3755/LT3755-1/LT3755-2 sense output current at the high side of the LED string. High side current sensing is the most exible scheme for driving LEDs, allowing boost, buck mode or buck-boost mode con guration. The PWM input provides LED dimming ratios of up to 3000:1, and the CTRL input provides additional analog dimming capability.