LM3445M

• LED dimming of a triac dim decoder circuit
• Application voltage range 80V_AC- 277V_AC
• Able to control LED current greater than 1A
• Adjustable switching frequency
• Low quiescent current
• Adaptively programmable off-time constant ripple current allows
• Thermal shutdown
• No 120Hz flicker
• Low profile 10-pin MSOP package or 14-pin SOIC
• Patent-pending drive architecture

illustrate

The LM3445 is an adaptive constant off-time AC/DC buck (step-down) constant current controller designed to be compatible with triacs. The LM3445 provides a constant current for high-power LEDs for lighting and includes a triac dimming decoder. The dim decoder allows extensive use of standard TRIAC dimmer LED dimming. High-frequency capability architecture that allows the use of small external passive components. The LM3445 includes a bleed circuit to ensure proper thyristor operation while allowing current to flow with low line voltage, enabling proper firing of triacs. The passive PFC circuit ensures good power factor, plots directly from the current cycle line, and provides a constant positive voltage to the buck regulator. Additional features include thermal shutdown, current limit, and V_CCUndervoltage lockout.

apply

• Vintage suitable for thyristor dimming
• Solid-state lighting
• Industrial and commercial lighting
• Residential lighting