The LT3761’s internal PWM dimming generator makes it ideal for driving high current LEDs, but it also has features making it suitable for charging batteries and supercapacitors. The device’s 4.5 V to 60 V input voltage range makes it ideal for a wide variety of applications, including automotive, industrial and architectural lighting. The LT3761 uses an external N-channel MOSFET and can drive up to fifteen 1 A white LEDs from a nominal 12 V input, delivering in excess of 50 watts. It incorporates a high-side current sense, enabling its use in boost mode, buck mode, buck-boost mode or SEPIC topologies. The LT3761 can deliver efficiencies of over 94% in the boost topology, eliminating the need for external heat sinking. A frequency adjust pin permits the user to program the frequency between 100 kHz and 1 MHz, optimizing efficiency while minimizing external component size and cost. Combined with a thermally enhanced MSOP-16 package, the LT3761 offers a compact high power LED driver solution.
The LT3761 has an internal PWM generator that delivers dimming ratios as high as 50:1 or it can utilize an external PWM signal, delivering dimming ratios of up to 3,000:1. For less demanding dimming requirements, the CTRL pin can be used to offer a 10:1 analog dimming range. Its fixed frequency, current-mode architecture offers stable operation over a wide range of supply and output voltages. Output short-circuit protection and open LED protection enhance system reliability. The LT3761’s ground-referenced voltage FB pin serves as the input for several LED protection features and also makes it possible for the converter to operate as a constant-voltage source for charging applications.
Availability and Pricing
The LT3761EMSE is available in a thermally enhanced MSOP-16 package. Pricing starts at $3.45 each. An extended temperature version, or I grade, the LT3761IMSE, is also available, priced starting at $3.86 each. Finally a high temperature or H grade option, the LT3761HMSE is also available, starting at $4.11