3 MHz buck in an 8-DSBGA — what you're working with
The TPS62311YZDR is a fixed 1.5 V output step-down (buck) regulator from Texas Instruments, switching at 3 MHz and rated for 500 mA continuous output. It integrates a synchronous rectifier, so no external Schottky diode is needed — the efficiency curve stays competitive down to light loads. The 8-DSBGA package (0.5 mm ball pitch) is the smallest footprint you'll find for this power class; it's the reason the part was chosen for space-constrained portable designs, but it also means the board layout and reflow profile need to match the DSBGA land pattern exactly.
Obsolete — the sourcing reality
If you are in a redesign window, the 3 MHz switching frequency and 500 mA output with a fixed 1.5 V rail are the parameters a replacement part must match; the DSBGA footprint is the tightest constraint for a pin-compatible swap.
The 8-DSBGA package is a wafer-level chip-scale package. The solder balls are the terminals — there are no leads.