A conversion circuit includes a main device including a first terminal, a second terminal and a control terminal, and a voltage control switching circuit including a first terminal configured to receive an first driving signal, a second terminal coupled to the control terminal of the main device and configured to transmit a second driving signal to drive the main device, and a reference terminal coupled to the second terminal of the main device. A current passing through the voltage control switching device is controlled in response to a voltage level of the reference terminal.