110-V LED controller offers spread-spectrum freq mod

The LT3795, a 110-V, high-side current-sense dc/dc converter designed to regulate a current or voltage to a constant value, drives high-brightness (HB) LEDs. Spread-spectrum frequency modulation reduces EMI emissions, while an internal PMOS switch driver provides short-circuit protection in boost and buck-boost topologies. Its 4.5 to 110-V input voltage range makes it appropriate for automotive, industrial and architectural lighting applications.

The LED controller uses an external low-side n-channel MOSFET and can drive up to 90 V of white LEDs from a nominal 12-V input, delivering 50 W. The controller incorporates a high-side current sense, enabling it to be used in boost, buck, buck-boost or SEPIC topologies. The device can deliver efficiencies over 94% in boost mode, minimizing the need for external heat sinking. The PWM dimming delivers constant LED color with dimming ranges of up to 3,000:1.