The Texas Instruments TPS61253AYFFR is a synchronous step-up converter that delivers a fixed 5V output from an input voltage range of 2.65V to 4.85V. It integrates a 3.3A switch and operates at a 3.5MHz switching frequency, allowing the use of small external inductors and capacitors.
3.3A switch and 3.5MHz frequency — sizing the passives
The 3.3A switch current rating sets the practical output current capability. For a 2.65V input to 5V output conversion, the maximum output current is roughly 1.5A, limited by the switch current and duty cycle. The 3.5MHz switching frequency shifts the inductor value down to the 0.47 µH to 2.2 µH range, and the output capacitor to 10 µF to 22 µF — small ceramic parts that fit the tight DSBGA footprint. The fixed 5V output eliminates the feedback resistor divider, saving two components and one feedback pin connection.
DSBGA package — layout and rework considerations
The 9-DSBGA package is a wafer-level chip-scale package — the solder balls are the only connection.
No official second source or pin-compatible cross-reference is listed, so the BOM relies on this single TI part number.