| 摘要 |
PROBLEM TO BE SOLVED: To provide a USB power supply device capable of suppressing drop of the bus voltage outputted from a receptacle.SOLUTION: A USB power supply device 100 supplies power to a USB power reception device 200, in compliance with USB (Universal Serial Bus) standard. A bus line 106 connects the output of a power supply circuit 102 and the USB power reception device 200. A switch SW1 is provided on the path of the bus line 106. A selector 140 selects one of the output voltage Vof the power supply circuit 102 or the bus voltage Vcloser to the USB power reception device 200 side than the switch SW1. A feedback circuit 104 performs feedback control of the power supply circuit 102, so that the voltage Vselected by the selector 140 approaches a set voltage V. A controller 110 controls the switch SW and selector 140, on the basis of the state of the USB power supply device 100.SELECTED DRAWING: Figure 2 |
