16-channel buck controller for multi-string LED backlighting
The LT3745EUJ-1#PBF from Analog Devices is a 16-channel DC/DC controller designed for PWM-dimming LED backlight and signage applications. It operates as a step-down (buck) topology and delivers up to 75 mA per channel, making it a fit for large-format LCD backlight panels or multi-zone signage where each LED string needs independent current regulation. The controller requires external MOSFETs and inductor(s) — it is not a monolithic driver, so the BOM includes those power-stage components.
Supply range and switching frequency — what they mean for the rail design
The input supply range spans 6 V to 55 V, which covers common automotive and industrial bus voltages (12 V, 24 V, 48 V) without an external pre-regulator. The switching frequency is programmable from 200 kHz to 1 MHz, letting the designer trade off inductor size against switching losses. A 55 V max input also means the part can survive load-dump transients on a nominal 48 V rail, though external TVS clamping is still recommended for sustained overvoltage events.
Temperature grade and package — deployment context
Rated for -40°C to 125°C (junction), the LT3745EUJ-1#PBF suits outdoor signage, engine-bay-adjacent automotive lighting, and industrial equipment where ambient temperatures exceed 85°C. The package is a 40-lead WFQFN with exposed pad (6 mm × 6 mm), which requires a thermal via array under the pad to keep junction temperature within limits at full 16-channel load. Surface-mount assembly is standard, but the exposed pad needs a solder-paste stencil opening matched to the datasheet footprint.
Lifecycle and sourcing
It is RoHS3 compliant. For a BOM line that needs 16-channel LED drive, this part can be specified into new designs without immediate lifecycle risk.