Triple-Output LED Driver Controller Delivers Over 250 W

Each channel of Linear Technology’s LT3797 triple-output dc-dc controller drives a wide range of LED power in either step-up, step-down, or SEPIC topologies. Its fixed-frequency, current-mode architecture supplies constant, accurately regulated LED current. Thanks to a 2.5- to 40-V input voltage range with transient ride through to 60 V, the device will find homes in automotive applications, which must operate through cold-crank, stop/start, and load-dump scenarios, as well as in industrial applications. In boost configuration, the controller powers three channels of up to 90 V of LEDs with currents in excess of 1 A, thus providing over 250 W of power from a nominal 12-V input with efficiencies up to 93%. An independent True Color PWM signal operates each of the three channels, enabling dimming ratios up to 3000:1. All channels integrate open-LED and short-circuit protection in boost mode. With a frequency-adjust pin, users can program the frequency between 100 kHz and 1 MHz to optimize efficiency and minimize external component size. The devices come in thermally enhanced 7- by 8-mm QFN packages.

LINEAR TECHNOLOGY CORP.