LM3444

Product Folder Sample & Buy Technical Documents Tools & Software Support & Community LM3444 SNVS682D – NOVEMBER 2010 – REVISED DECEMBER 2015 LM3444 AC-DC Offline LED Driver 1 Features 1 Application Voltage Range: 80 VAC to 277 VAC Capable of Controlling LED Currents Greater than 1 A Adjustable Switching Frequency Low Quiescent Current Adaptive Programmable Off-Time Allows for Constant Ripple Current Thermal Shutdown No Flicker at 120 Hz Low-Profile 10-Pin VSSOP Package or 8-Lead SOIC Package Patented Drive Architecture 2 Applications Solid State Lighting Industrial and Commercial Lighting Residential Lighting SPACE Typical LM3444 LED Driver Application Circuit V+ D3 VBUCK BR1 C7 + D9 C10 R2 D4 D8 C9 + VLED C12 - R4 VAC Q1 D1 D2 C5 VLEDD10 Q3 LM3444 L2 1 NC U1 NC 10 2 NC VCC 9 ICOLL 3 NC GATE 8 Q2 3 Description The LM3444 is an adaptive constant off-time AC/DC buck (step-down) constant current controller that provides a constant current for illuminating high power LEDs. The high-frequency capable architecture allows the use of small external passive components. A passive PFC circuit ensures good power factor by drawing current directly from the line for most of the cycle, and provides a constant positive voltage to the buck regulator. Additional features include thermal shutdown, current limit and VCC undervoltage lockout. The LM3444 is available in a low profile 10-pin VSSOP package or an 8-lead SOIC package. Device Inform...