Linear LED driver in SOT-26 — 100 mA constant-current sink for automotive lighting
The BCR402UW6-7 is a linear LED driver from Diodes Incorporated, delivering a regulated 100 mA constant-current output from a single channel. It integrates the switching element internally, so no external FET is needed — the SOT-26 package holds the pass device and control logic on one die. Rated for a maximum output voltage of 40 V and a supply range from 1.4 V up to 40 V, this part covers the common automotive LED rail voltages — 12 V nominal, 24 V truck systems, and the 40 V load-dump transient without an external clamp.
PWM dimming at 25 kHz — no audible noise in cabin lighting
The driver supports PWM dimming up to 25 kHz. At this frequency the switching cycle is above the human hearing range, so there is no audible coil whine or buzzer effect in interior or exterior automotive LED modules. The linear topology means the output current ramps cleanly with the PWM duty cycle without the ripple of a switching regulator. Target applications include lighting and signage — for automotive this translates to tail lights, daytime running lights, interior ambient strips, and backlit switches where constant-current regulation and dimming are required.
Package and board-fit — SOT-23-6 / SOT-26 footprint
Housed in a SOT-23-6 package (also designated SOT-26 by the supplier), the BCR402UW6-7 occupies a 2.9 mm × 1.6 mm footprint with a 0.95 mm pitch. The six-pin layout breaks out the LED cathode, supply, and ground — the thermal pad is the die attach, so the copper area under the package on the PCB sets the effective thermal resistance. The TR variant is the standard production reel for pick-and-place; CT is for prototyping or low-volume builds. Both are stocked under the same ordering code.