Boost converter with programmable output and synchronous rectification
The TPS61291DRVR is a step-up (boost) DC-DC converter from Texas Instruments that delivers a programmable output voltage — selectable between 2.5 V, 3.0 V, or 3.3 V — from an input as low as 0.9 V up to 5 V. Its 700 mA internal switch rating sets the practical load ceiling; the integrated synchronous rectifier improves efficiency by replacing the external Schottky diode typical of simpler boost topologies.
With a minimum input of 0.9 V, this part can start up from a near-depleted single-cell alkaline or NiMH battery. The 700 mA switch current is the peak current the internal power FET conducts during the on-time — actual output current depends on input-to-output voltage ratio, switching losses, and inductor selection. For a 3.3 V output from a 1.8 V rail, expect around 350-400 mA continuous output before hitting the switch limit.
Package and footprint: design-in notes for the 6-WSON
That pad must be soldered to the board ground for both thermal relief and electrical connection; a floating pad degrades thermal performance and may cause the regulator to thermal-cycle at high load.