Controller identity and topology flexibility
The LT3761AEMSE#TRPBF is a DC DC LED driver controller from the True Color PWM™ family, designed for constant-current LED strings where dimming linearity and color stability matter. It supports four topologies — boost, buck, SEPIC, and flyback — so a single BOM position can serve a boost-configured high-bay light and a buck-configured sign backlight by changing only the external power stage. The controller lacks an internal switch, meaning the FET and inductor are external; this lets the designer size the power stage for the actual LED string voltage and current without being locked into a monolithic current limit.
Dimming methods and switching frequency range
Both analog and PWM dimming are supported, which is the standard combination for RGB color-mixing fixtures: analog sets the DC current floor, PWM modulates the on-time for color temperature blending without chromaticity shift. The oscillator runs from 100 kHz to 1 MHz, settable with a single resistor. At 1 MHz the inductor shrinks to a small footprint value for space-constrained PCBAs; at 100 kHz the switching losses drop, suiting higher input voltages or thermally limited enclosures. A single output drives the external gate driver — the controller itself does not carry the switching current, so the thermal dissipation stays in the external FET, not the IC.
Lifecycle and compliance posture
The tape-and-reel suffix (TRPBF) means it ships on 13-inch reels for automated pick-and-place; cut-tape quantities are also available for prototyping.