In general, the embodiments introduce a pre-charge state between an idle state and an active state. The method for switching a working mode includes: determining, according to the osvc key value in the registry of a host device, that a driver for a second working mode is installed on the host device, after the USB device is connected to the host device; and switching the current working state of the USB device from a first working mode to the second working mode. The first magnetic member faces the second magnetic member. In order to compensate for analog delay and slewing, it is noted that changing the sampling point in the ADC is equivalent to introducing a phase change in the output.