The AP1506 series are monolithic IC designed for a step-down. DC/DC converter, and own the ability of driving a 3A load without external transistor.
$1.50
Buck Switching Regulator IC Positive Fixed 5V 1 Output 3A TO-263-6, D2PAK (5 Leads + Tab), TO-263BA. Datasheet. Datasheet. EDA/CAD Models. AP1506-50K5G-13 ...
$1.49
AP1506-50K5G-13 Diodes Incorporated Switching Voltage Regulators SW REG CNV BUCK ASYN 150K 4.5V 22V 5.0V datasheet, inventory, & pricing.