| 摘要 |
PROBLEM TO BE SOLVED: To reduce power consumption.SOLUTION: There is provided a power supply 200 which supplies a bus voltage Vto a detachable device 500. A DC/DC converter 202 generates a DC voltage Vwhich is used as a bus voltage V. A USB controller 300 receives the DC voltage Vas power, and detects the existence or non-existence of the connection of the device 500. The DC/DC converter 202 generates (i) when the device 500 is detected, a DC voltage Vhaving a normal voltage level, and (ii) when the device 500 is not detected, a DC voltage Vhaving a voltage level higher than the minimum operating voltage of the USB controller 300.SELECTED DRAWING: Figure 1 |
