(Hong Kong)
Product Summary
The LM3445MM is an adaptive constant off-time AC/DC buck (step-down) constant current controller designed to be compatible with triac dimmers. The LM3445MM provides a constant current for illuminating high power LEDs and includes a triacdim decoder. The dim decoder allows wide range LED dimming using standard triac dimmers. The high frequency capable architecture allows the use of small external passive components. The LM3445MM includes a bleeder circuit to ensure proper triac operation by allowing current flow while the line voltage is low to enable proper firing of the triac. 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 under-voltage lockout. The LM3445MM can be applied in retro fit triac dimming, solid state lighting, industrial and commercial lighting, and residential lighting.
Parametrics
LM3445MM absolute maximum ratings: (1)BLDR to GND: -0.3V to +17V; (2)VCC, GATE, FLTR1 to GND: -0.3V to +14V; (3)ISNS to GND: -0.3V to +2.5V; (4)ASNS, DIM, FLTR2, COFF to GND: -0.3V to +7.0V; (5)COFF Input Current: 100mA; (6)Continuous Power Dissipation: Internally Limited; (7)Junction Temperature (TJ-MAX): 150°C; (8)Storage Temperature Range: -65°C to +150°C; (9)Maximum Lead Temp.Range (Soldering): 260°C.
Features
LM3445MM features: (1)Triac dim decoder circuit for LED dimming; (2)Application voltage range 80VAC – 277VAC; (3)Capable of controlling LED currents greater than 1A; (4)Adjustable switching frequency; (5)Low quiescent current; (6)Adaptive programmable off-time allows for constant ripple current; (7)Thermal shutdown; (8)No 120Hz flicker; (9)Low profile 10 pin MSOP Package or 14 pin SOIC; (10)Patent pending drive architecture.
Diagrams
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 LM3445MM/NOPB |
National Semiconductor (TI) |
LED Lighting Drivers TRIAC DIMMABLE OFF LINE LED DRVR |
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LM3445MMX/NOPB |
National Semiconductor (TI) |
LED Lighting Drivers |
Data Sheet |
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