0.3 V minimum input — the battery-extraction boost
The TPS61200DRCRG4 is a synchronous step-up (boost) converter from Texas Instruments that starts up and regulates from an input voltage as low as 0.3 V. The 1.2 A switch current limit sets the output power ceiling — at 3.3 V out from a 1.5 V input, budget around 1.5 W continuous before the switch hits its limit.
Synchronous rectification — one less Schottky on the BOM
This part integrates a synchronous rectifier, so there is no external Schottky diode in the boost path. That saves a component, shrinks the layout, and improves efficiency at light loads compared to a non-synchronous boost with a discrete diode. The switching frequency runs between 1.25 MHz and 1.65 MHz, which keeps the inductor small — typically a 2.2 µH to 4.7 µH shielded part in the 3x3 mm footprint.
10-VSON exposed pad — thermal design is not optional
The package is a 10-VFDFN with an exposed pad, also called 10-VSON (3x3 mm). Surface-mount assembly with standard lead-free reflow — the exposed pad does not require a special profile, but the solder stencil aperture under the pad should be segmented to avoid voiding.