5 A switch boost in a 1.67 mm BGA
The TPS61281AYFFT from Texas Instruments is a synchronous step-up (boost) converter that integrates a 5 A switch, letting it deliver useful output current from a single Li-ion cell or a 2.3 V to 4.85 V input rail.
Switching at 2.3 MHz shrinks the passives
The 2.3 MHz switching frequency lets the designer use a small inductor (typically 1 µH to 2.2 µH) and low-value ceramic output capacitors, keeping the total solution footprint tight around the 16-DSBGA package that measures just 1.67 x 1.67 mm. Synchronous rectification cuts the forward-drop loss of a Schottky diode, improving efficiency especially at moderate loads where the boost spends most of its operating time.
Obsolete — sourcing from surplus and broker channels
No official successor part is listed on the lifecycle record, so any replacement will require a pin-compatible or function-compatible cross-reference from the current TI boost converter portfolio. Expect to work with surplus stock or last-time-buy inventory held by brokers.