AX88172A_EXPRESSCARD-TO-REVMII_-20105 4 3 2 1 Note: This schematic is for your reference purpose only This block of circuit should be implemented on the external device that was connected to AX88172A through Rev-MII or Rev-RMII interface AX88172A can use the GPIO_0 pin to control the switching regulator power of external device to reduce the power consumption for USB-IF Bus-power mode test External Device Power VDD1_8 U5 4 VIN GND EN SW 3 L3 2.2uH R11 200k C41 22uF/10V R13 100k C43 0.1uF C1 0.1uF VCC3_3 Reference Transformer Part No. list YL2J201A YuTai Electronics Co.,LTD TEL:86-574-63620701,63621610 http;//www.yutai-elec.com EMAIL：nico_yu@yeah.net ON C40 4.7uF/16V C42 0.1uF OFF GPIO_0 1 Active high 2 FB 5 MP1556DJ Switching regulator D VCC3_3 R5 330 SPEED_LED 12 11 U6 D The switching regulator reference……