A conversion circuit includes a main device, a voltage control switching circuit and a trigger circuit. The trigger circuit includes an output terminal and a sense terminal. The sense terminal is electrically connected to the control terminal of the main device. The voltage control switching circuit includes a first terminal, a second terminal and a control terminal. A first terminal is configured to receive an original signal. A second terminal is connected to a control terminal of the main device, and is configured to transmit a driving signal to drive the main device. A control terminal is connected to the main device and the output terminal. The driving signal has a first voltage level generated by the voltage control switching circuit in response to a voltage level at the control terminal of the voltage control switching circuit.