LM3445MM

The LM3445MM from Texas Instruments is an adaptive constant off-time AC/DC buck (step-down) constant current controller. It is specifically designed for compatibility with TRIAC dimmers, enabling wide-range LED dimming using standard TRIAC dimmers. This controller provides a constant current for illuminating high-power LEDs and includes an integrated TRIAC dim decoder circuit.

Key electrical specifications include an input voltage range of 8 V to 12 V AC/DC, with an output voltage capability up to 60 V and a maximum output current of 2 A. The device features adjustable switching frequency, enable/shutdown functionality, and thermal shutdown protection. Its operating temperature range spans from -40°C to 125°C.

The LM3445MM supports multiple dimming methods, including Forward Phase (Triac), PWM, and Reverse Phase. It is available in VSSOP (10-pin) and SOIC (14-pin) packages, both suitable for surface mounting. The TRIAC dim decoder circuit operates within a voltage range of 80 V AC to 277 V AC and is capable of controlling LED currents greater than 1 A, offering adaptive programmable off-time for constant ripple current control and no 120-Hz flicker.

This LED driver is well-suited for illumination applications requiring TRIAC dimming compatibility, such as residential lighting and commercial fixtures. Its patented drive architecture and adaptive off-time control contribute to efficient LED current regulation.