LT3755-1 Datasheet | Linear Technology

LT3755/LT3755-1/LT3755-2 40VIN, 75VOUT LED Controllers Features n 3000:1 True Color PWM™ Dimming n Wide Input Voltage Range: 4.5V to 40V n Output Voltage Up to 75V n Constant-Current and Constant-Voltage Regulation n 100m V High Side Current Sense n Drives LEDs in Boost, Buck Mode, Buck-Boost Mode, SEPIC or Flyback Topology n Adjustable Frequency: 100k Hz 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 n AEC-Q100 Qualified For Automotive Applications 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 controllers 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 fixed 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 100k Hz to 1MHz to optimize efficiency, performance or external ponent 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 flexible scheme for driving LEDs, allowing boost, buck mode or buck-boost mode configuration. The PWM input provides LED dimming ratios of up to 3000:1, and the CTRL input provides additional analog dimming capability. All registered trademarks and trademarks are the property of their respective owners....