Boost LED driver with integrated switch — what the 1.1 A rating buys you
The TPS61166DSKR is a step-up (boost) DC-DC regulator from Texas Instruments, purpose-built for driving white LED backlight strings in small-to-medium displays. The integrated switch handles 1.1 A peak current, which translates to enough headroom for a string of 6 to 8 series LEDs at typical forward currents — the exact count depends on the LED Vf and the 17 V output ceiling. PWM dimming input is on the spec sheet, so the brightness control comes from a logic-level PWM signal rather than an analog voltage — this keeps the colour temperature stable across the dimming range, which matters for display uniformity in handheld and portable equipment.
The 1.2 MHz switching frequency keeps the inductor small — a 4.7 µH to 10 µH shielded type in a 2.0×2.5 mm package is typical — and pushes the switching noise above the audio band. That covers outdoor handhelds, point-of-sale terminals, and portable medical gear, but not under-hood automotive or engine-bay environments — those would need an AEC-Q100 rated part.
Package and footprint — what to watch on the 10-WFDFN
The 10-WFDFN Exposed Pad package (2.5×2.5 mm body, 10-SON supplier package) demands a thermal pad on the PCB — the exposed paddle is the primary heat path for the integrated switch. The datasheet layout recommendation calls for a 2.0×2.0 mm pad with at least four vias to the ground plane; skipping the thermal pad connection derates the output current capability.