Boost converter that starts below a dead battery
The Texas Instruments TPS61200DRCTG4 is a synchronous step-up (boost) converter with a minimum input voltage of 0.3 V — low enough to extract usable energy from a single alkaline cell that has dropped below its nominal 1.5 V endpoint, or from a Li-ion cell deep into its discharge curve.
0.3 V minimum input — the so-what for battery-powered BOMs
Most boost converters cut out at 0.8 V or higher. The TPS61200's 0.3 V minimum input means it can start and regulate from a single NiMH, alkaline, or LiFePO4 cell that is nearly fully discharged. For a design targeting a 3.3 V rail from one cell, this extends usable battery life well past the point where a conventional boost would drop out. The trade-off is the input current at low Vin — at 0.3 V in and 3.3 V out at 100 mA, the switch current approaches the 1.2 A limit, so output power is capped at roughly 300 mW at the lowest input. The switching frequency runs between 1.25 MHz and 1.65 MHz, which keeps the inductor small — a 2.2 µH to 4.7 µH shielded ferrite is typical.
Package and thermal: 10-VSON with exposed pad
The TPS61200DRCTG4 is supplied in a 10-VFDFN exposed-pad package, also designated as 10-VSON (3x3 mm).
The base product number is TPS61200, and the DRCTG4 suffix denotes the Tape & Reel (TR) shipping form in the 10-VSON package.