LED driver controller with wide topology support
The LT3755EMSE#TRPBF from Analog Devices is a DC DC controller designed for LED driving, supporting Buck, Boost, Flyback, and SEPIC topologies. It accepts an input supply from 4.5 V up to 40 V, making it suitable for automotive, industrial, and general-purpose lighting power rails where the bus voltage varies. The controller operates with a switching frequency programmable from 100 kHz to 1 MHz, allowing the designer to trade off inductor size against switching losses. The 1 MHz upper end keeps the magnetics small for space-constrained boards.
Dimming and output control
Both analog and PWM dimming are supported, giving the BOM engineer flexibility in the LED current control loop. PWM dimming delivers a wider contrast ratio without color shift, while analog dimming simplifies the control interface when a PWM source is not available. The part is a controller only — it requires an external N-channel MOSFET and sense resistor to form the power stage. This lets the designer scale the output current and voltage beyond what an integrated-switch part can deliver, sizing the external FET to the thermal budget of the specific LED string.
Package and thermal management
Housed in a 16-lead MSOP with an exposed pad (16-MSOP-EP), the package footprint is 3.00 mm wide. The operating junction temperature range is 0°C to 125°C. This commercial-grade range covers most indoor and well-ventilated enclosures but does not extend to the -40°C cold crank typical of automotive exterior lighting — check the ambient temperature profile of the end system.
Active production and compliance
Supplied in Tape & Reel (TR) packaging — the #TRPBF suffix indicates reel quantity suitable for automated pick-and-place assembly. Cut Tape (CT) options are also listed for prototype or low-volume builds.