Boost regulator for LED backlight — what the 28 V output and 215 mA switch mean
The TPS61041DRVT is a current-mode step-up (boost) DC-DC regulator from Texas Instruments, designed primarily to drive white LED backlight strings in small portable displays. Its 28 V output ceiling lets you stack up to seven or eight series white LEDs from a single Li-ion cell, while the 215 mA switch current limit sets the maximum LED string current — expect to derate that figure as the output voltage climbs, since the switch dissipation scales with (Vout - Vin) × Iswitch. The input voltage range spans 1.8 V to 6 V, covering a single Li-ion cell from full charge down to near-depleted, as well as two alkaline cells or a regulated 3.3 V / 5 V rail. PWM dimming is built in — a logic-level PWM signal on the EN pin modulates the LED current directly, so a microcontroller can control brightness without an external DAC or analog voltage.
Package and thermal — 6-WSON with exposed pad
The pad is the main heat path — a few vias under the pad to an inner-layer copper pour keep the junction temperature in check, especially when running near the 215 mA switch limit at high ambient. Surface-mount assembly is standard; the 2x2 mm footprint fits into compact layouts alongside the inductor and input/output capacitors.