The PL2731 is a SuperSpeed USB to Single LUN SD/MMC card reader. It supports USB Mass Storage Class Bulk Only Transfer specification to access Secure Digital card up to SD3.0 UHS-I SDR104. The PL2731 integrates USB transceiver, LDO regulator for SD card power, SD UHS-I IO interface regulator, logic core and GPIO to achieve a very low BOM cost. The controller supports optional SPI flash interface for system firmware.