Datenbogen (LM3445-230VFLBK/NOPB)InhaltsverzeichnisFEATURES1APPLICATIONS1DESCRIPTION1Typical LM3445 LED Driver Application Circuit1Connection Diagram2ABSOLUTE MAXIMUM RATINGS3OPERATING CONDITIONS3ELECTRICAL CHARACTERISTICS3TYPICAL PERFORMANCE CHARACTERISTICS5SIMPLIFIED INTERNAL BLOCK DIAGRAM7APPLICATION INFORMATION7FUNCTIONAL DESCRIPTION7OVERVIEW OF PHASE CONTROL DIMMING7THEORY OF OPERATION9SENSING THE RECTIFIED TRIAC WAVEFORM10LM3445 LINE SENSING CIRCUITRY10TRIAC HOLDING CURRENT RESISTOR11ANGLE DETECT12BLEEDER12FLTR1 PIN12DIM DECODER12VALLEY-FILL CIRCUIT13VALLEY-FILL OPERATION13BUCK CONVERTER14OVERVIEW OF CONSTANT OFF-TIME CONTROL15MASTER/SLAVE OPERATION16MASTER/SLAVE CONFIGURATION16MASTER BOARD MODIFICATIONS16SLAVE BOARD(S) MODIFICATIONS16MASTER/SLAVE(S) INTERCONNECTION16MASTER/SLAVE THEORY OF OPERATION16MASTER/SLAVE CONNECTION DIAGRAM17MASTER/SLAVE BLOCK DIAGRAMS18THERMAL SHUTDOWN19DESIGN GUIDE20DETERMINING DUTY-CYCLE (D)20CALCULATING OFF-TIME20SETTING THE SWITCHING FREQUENCY20INDUCTOR SELECTION21SETTING THE LED CURRENT23VALLEY FILL CAPACITORS23Determining the capacitance value of the valley-fill capacitors24Determining Maximum Number of Series Connected LEDs Allowed24OUTPUT CAPACITOR26SWITCHING MOSFET26RE-CIRCULATING DIODE27DESIGN EXAMPLE28LM3445 DESIGN EXAMPLE 1 INPUT = 90VAC TO 135VAC, VLED = 7 x HB LED STRING APPLICATION @ 400 MA30Revision History32Größe: 1,08 MBSeiten: 39Language: EnglishHandbuch öffnen