3A programmable buck in a 2.02×1.31 mm WLCSP
The FAN53526UC64X is a 3A continuous-output step-down (buck) regulator from onsemi's TinyBuck® series, switching at 2.4 MHz and fitting into a 15-bump WLCSP measuring 2.02×1.31 mm. Integrated synchronous rectification eliminates the external Schottky diode, keeping the BOM count low and efficiency high at the 2.4 MHz switching frequency.
The small package means the thermal dissipation path is primarily through the solder balls to the PCB copper — a solid ground-plane connection under the device is expected for the 3 A output.