Boost regulator for LED strings and bias rails
The TPS61046YFFR is a step-up (boost) regulator from Texas Instruments, delivering up to 1.2 A output current with an adjustable output voltage up to 28 V. Switching at 1.05 MHz, it keeps the external inductor small — typically 4.7 µH to 10 µH — which matters when board space is tight. The adjustable output (minimum 4.5 V) lets you set the voltage to match a specific LED string length or a bias rail, rather than being locked to a fixed value. No synchronous rectifier means the external Schottky diode must handle the peak current — factor that into the BOM diode selection.
The 6-bump DSBGA (0.4 mm pitch) demands a controlled reflow profile and careful PCB layout — the thermal pad is the backside of the die, so via placement under the package is critical for heat sinking. Compared to the LM2750LD-ADJ/NOPB charge pump (120 mA max, 1.7 MHz), the TPS61046YFFR delivers 10× the output current and a higher output voltage, making it a better fit for driving multiple series LEDs rather than a single low-current rail.