LM3699

Product Folder Sample & Buy Technical Documents Tools & Software Support & Community LM3699 SNVS821A – JANUARY 2014 – REVISED MARCH 2014 LM3699 High-Efficiency White LED Driver 1 Features 1 Drives Parallel High-Voltage LED Strings for Display or Keypad Lighting Boost Converter up to 90% Efficiency Four User-Selectable Full-Scale Current Settings (20.2 mA, 18.6 mA, 17.0 mA, 15.4 mA) Quick-Dimming Enable Terminal (ILOW) Simple PWM Duty Cycle Control 24-V Overvoltage Protection Threshold Fixed 1-MHz Switching Frequency Integrated 1-A/40-V MOSFET Three Current Sink Terminals Adaptive Boost Output to LED Voltages Thermal Shutdown Protection 29-mm2 Total Solution Size 3 Description The LM3699 is a three-string, high-efficiency, PWMcontrolled power source for display backlight or keypad LEDs in smartphone handsets. The highvoltage inductive boost converter with integrated 1-A, 40-V MOSFET provides the power for three series LED strings. The boost output automatically adjusts to LED forward voltage to minimize headroom voltage and effectively improve LED efficiency. The ILOW terminal provides a method to quickly reduce LED brightness during camera flash operation. The LM3699 has integrated overvoltage, overcurrent, and thermal protection. The device operates over a 2.7-V to 5.5-V input voltage range and a −40°C to 85°C temperature range. 2 Applications Power Source for Smart Phone Illumination Display or Keypad Illumination Device Information ORDE...