Buck-boost LED driver offers wide input voltage range

Milpitas, Calif.—Designed to drive high current LEDs, Linear Technology's 100V, high-side current sense DC/DC converter features a 6V to 100V input voltage range that makes it well-suited for a wide variety of applications, including automotive, industrial and architectural lighting.

The LT3756 uses an external N-channel MOSFET and can drive up to 20 1A white LEDs from a nominal 12V input, delivering in excess of 70 watts. It incorporates a high-side current sense, enabling it to be used in boost, buck, buck-boost or SEPIC and flyback topologies. The LT3756 can deliver efficiencies of over 94% in boost mode, eliminating any need for external heat sinking. A frequency adjust pin permits the user to program the frequency between 100kHz and 1MHz, optimizing efficiency while minimizing external component size and cost.

The LT3756 uses True Color PWM dimming, delivering constant LED color with dimming ranges up to 3,000:1. For less demanding requirements, the CTRL pin can be used to offer a 10:1 analog dimming range. Its fixed frequency, current mode architecture ensures stable operation over a wide range of supply and output voltages. A ground referenced voltage FB pin serves as the input for several LED protection features, making it possible for the converter to operate as a constant-voltage source.

Two versions of the LT3756 are available. The standard LT3756 offers an Open LED Status pin, and the LT3756-1 replaces the Open LED Status pin with a frequency synchronization pin.

Both the LT3756EUD and LT3756EUD-1 are available from stock in a 16-pin 3mm x 3mm QFN package. The LT3756EMSE and LT3756EMSE-1 are both available in a thermally enhanced MSOP-16E package. Pricing starts at $2.90 each for the QFN package options and $3.00 each for the MSOP-16E options. Also available from stock are extended temperature versions, or "I" grades, namely the LT3756IUD and LT3755IUD-1, with pricing starting at $3.30 each, in 1,000-piece quantities. Similarly, "I" grade options of the MSOP-16 versions, the LT3756IMSE and LT3756IMSE-1 are priced starting at $3.40 each in 1,000-piece quantities.

Datasheet: Click here.

Linear Technology, www.linear.com